diff --git a/soundio/soundio.h b/soundio/soundio.h
index 7cfd6ad..4b648f6 100644
--- a/soundio/soundio.h
+++ b/soundio/soundio.h
@@ -359,7 +359,7 @@ struct SoundIo {
     /// * #SoundIoErrorSystemResources
     /// * #SoundIoErrorOpeningDevice - unexpected problem accessing device
     ///   information
-    void (*on_backend_disconnect)(struct SoundIo *, int err);
+    void (*on_backend_disconnect)(struct SoundIo *, enum SoundIoError err);
     /// Optional callback. Called from an unknown thread that you should not use
     /// to call any soundio functions. You may use this to signal a condition
     /// variable to wake up. Called when ::soundio_wait_events would be woken up.
@@ -502,7 +502,7 @@ struct SoundIoDevice {
     /// Possible errors:
     /// * #SoundIoErrorOpeningDevice
     /// * #SoundIoErrorNoMem
-    int probe_error;
+    enum SoundIoError probe_error;
 };
 
 /// The size of this struct is not part of the API or ABI.
@@ -580,7 +580,7 @@ struct SoundIoOutStream {
     /// If you do not supply error_callback, the default callback will print
     /// a message to stderr and then call `abort`.
     /// This is called from the SoundIoOutStream::write_callback thread context.
-    void (*error_callback)(struct SoundIoOutStream *, int err);
+    void (*error_callback)(struct SoundIoOutStream *, enum SoundIoError err);
 
     /// Optional: Name of the stream. Defaults to "SoundIoOutStream"
     /// PulseAudio uses this for the stream name.
@@ -604,7 +604,7 @@ struct SoundIoOutStream {
     /// If setting the channel layout fails for some reason, this field is set
     /// to an error code. Possible error codes are:
     /// * #SoundIoErrorIncompatibleDevice
-    int layout_error;
+    enum SoundIoError layout_error;
 };
 
 /// The size of this struct is not part of the API or ABI.
@@ -664,7 +664,7 @@ struct SoundIoInStream {
     /// If you do not supply `error_callback`, the default callback will print
     /// a message to stderr and then abort().
     /// This is called from the SoundIoInStream::read_callback thread context.
-    void (*error_callback)(struct SoundIoInStream *, int err);
+    void (*error_callback)(struct SoundIoInStream *, enum SoundIoError err);
 
     /// Optional: Name of the stream. Defaults to "SoundIoInStream";
     /// PulseAudio uses this for the stream name.
@@ -686,7 +686,7 @@ struct SoundIoInStream {
 
     /// If setting the channel layout fails for some reason, this field is set
     /// to an error code. Possible error codes are: #SoundIoErrorIncompatibleDevice
-    int layout_error;
+    enum SoundIoError layout_error;
 };
 
 /// See also ::soundio_version_major, ::soundio_version_minor, ::soundio_version_patch
@@ -713,7 +713,7 @@ SOUNDIO_EXPORT void soundio_destroy(struct SoundIo *soundio);
 /// * #SoundIoErrorSystemResources
 /// * #SoundIoErrorNoSuchClient - when JACK returns `JackNoSuchClient`
 /// See also ::soundio_disconnect
-SOUNDIO_EXPORT int soundio_connect(struct SoundIo *soundio);
+SOUNDIO_EXPORT enum SoundIoError soundio_connect(struct SoundIo *soundio);
 /// Instead of calling ::soundio_connect you may call this function to try a
 /// specific backend.
 /// Possible errors:
@@ -725,11 +725,11 @@ SOUNDIO_EXPORT int soundio_connect(struct SoundIo *soundio);
 /// * #SoundIoErrorInitAudioBackend - requested `backend` is not active
 /// * #SoundIoErrorBackendDisconnected - backend disconnected while connecting
 /// See also ::soundio_disconnect
-SOUNDIO_EXPORT int soundio_connect_backend(struct SoundIo *soundio, enum SoundIoBackend backend);
+SOUNDIO_EXPORT enum SoundIoError soundio_connect_backend(struct SoundIo *soundio, enum SoundIoBackend backend);
 SOUNDIO_EXPORT void soundio_disconnect(struct SoundIo *soundio);
 
 /// Get a string representation of a #SoundIoError
-SOUNDIO_EXPORT const char *soundio_strerror(int error);
+SOUNDIO_EXPORT const char *soundio_strerror(enum SoundIoError error);
 /// Get a string representation of a #SoundIoBackend
 SOUNDIO_EXPORT const char *soundio_backend_name(enum SoundIoBackend backend);
 
@@ -962,7 +962,7 @@ SOUNDIO_EXPORT void soundio_outstream_destroy(struct SoundIoOutStream *outstream
 ///   greater than the number of channels the backend can handle.
 /// * #SoundIoErrorIncompatibleDevice - stream parameters requested are not
 ///   compatible with the chosen device.
-SOUNDIO_EXPORT int soundio_outstream_open(struct SoundIoOutStream *outstream);
+SOUNDIO_EXPORT enum SoundIoError soundio_outstream_open(struct SoundIoOutStream *outstream);
 
 /// After you call this function, SoundIoOutStream::write_callback will be called.
 ///
@@ -973,7 +973,7 @@ SOUNDIO_EXPORT int soundio_outstream_open(struct SoundIoOutStream *outstream);
 /// * #SoundIoErrorNoMem
 /// * #SoundIoErrorSystemResources
 /// * #SoundIoErrorBackendDisconnected
-SOUNDIO_EXPORT int soundio_outstream_start(struct SoundIoOutStream *outstream);
+SOUNDIO_EXPORT enum SoundIoError soundio_outstream_start(struct SoundIoOutStream *outstream);
 
 /// Call this function when you are ready to begin writing to the device buffer.
 ///  * `outstream` - (in) The output stream you want to write to.
@@ -1005,7 +1005,7 @@ SOUNDIO_EXPORT int soundio_outstream_start(struct SoundIoOutStream *outstream);
 /// * #SoundIoErrorIncompatibleDevice - in rare cases it might just now
 ///   be discovered that the device uses non-byte-aligned access, in which
 ///   case this error code is returned.
-SOUNDIO_EXPORT int soundio_outstream_begin_write(struct SoundIoOutStream *outstream,
+SOUNDIO_EXPORT enum SoundIoError soundio_outstream_begin_write(struct SoundIoOutStream *outstream,
         struct SoundIoChannelArea **areas, int *frame_count);
 
 /// Commits the write that you began with ::soundio_outstream_begin_write.
@@ -1017,7 +1017,7 @@ SOUNDIO_EXPORT int soundio_outstream_begin_write(struct SoundIoOutStream *outstr
 ///   also get a SoundIoOutStream::underflow_callback, and you might not get
 ///   this error code when an underflow occurs. Unlike #SoundIoErrorStreaming,
 ///   the outstream is still in a valid state and streaming can continue.
-SOUNDIO_EXPORT int soundio_outstream_end_write(struct SoundIoOutStream *outstream);
+SOUNDIO_EXPORT enum SoundIoError soundio_outstream_end_write(struct SoundIoOutStream *outstream);
 
 /// Clears the output stream buffer.
 /// This function can be called from any thread.
@@ -1032,7 +1032,7 @@ SOUNDIO_EXPORT int soundio_outstream_end_write(struct SoundIoOutStream *outstrea
 /// * #SoundIoErrorStreaming
 /// * #SoundIoErrorIncompatibleBackend
 /// * #SoundIoErrorIncompatibleDevice
-SOUNDIO_EXPORT int soundio_outstream_clear_buffer(struct SoundIoOutStream *outstream);
+SOUNDIO_EXPORT enum SoundIoError soundio_outstream_clear_buffer(struct SoundIoOutStream *outstream);
 
 /// If the underlying backend and device support pausing, this pauses the
 /// stream. SoundIoOutStream::write_callback may be called a few more times if
@@ -1053,7 +1053,7 @@ SOUNDIO_EXPORT int soundio_outstream_clear_buffer(struct SoundIoOutStream *outst
 /// * #SoundIoErrorIncompatibleBackend - backend does not support
 ///   pausing/unpausing.
 /// * #SoundIoErrorInvalid - outstream not opened and started
-SOUNDIO_EXPORT int soundio_outstream_pause(struct SoundIoOutStream *outstream, bool pause);
+SOUNDIO_EXPORT enum SoundIoError soundio_outstream_pause(struct SoundIoOutStream *outstream, bool pause);
 
 /// Obtain the total number of seconds that the next frame written after the
 /// last frame written with ::soundio_outstream_end_write will take to become
@@ -1066,7 +1066,7 @@ SOUNDIO_EXPORT int soundio_outstream_pause(struct SoundIoOutStream *outstream, b
 ///
 /// Possible errors:
 /// * #SoundIoErrorStreaming
-SOUNDIO_EXPORT int soundio_outstream_get_latency(struct SoundIoOutStream *outstream,
+SOUNDIO_EXPORT enum SoundIoError soundio_outstream_get_latency(struct SoundIoOutStream *outstream,
         double *out_latency);
 
 
@@ -1098,7 +1098,7 @@ SOUNDIO_EXPORT void soundio_instream_destroy(struct SoundIoInStream *instream);
 /// * #SoundIoErrorNoSuchClient
 /// * #SoundIoErrorIncompatibleBackend
 /// * #SoundIoErrorIncompatibleDevice
-SOUNDIO_EXPORT int soundio_instream_open(struct SoundIoInStream *instream);
+SOUNDIO_EXPORT enum SoundIoError soundio_instream_open(struct SoundIoInStream *instream);
 
 /// After you call this function, SoundIoInStream::read_callback will be called.
 ///
@@ -1107,7 +1107,7 @@ SOUNDIO_EXPORT int soundio_instream_open(struct SoundIoInStream *instream);
 /// * #SoundIoErrorStreaming
 /// * #SoundIoErrorOpeningDevice
 /// * #SoundIoErrorSystemResources
-SOUNDIO_EXPORT int soundio_instream_start(struct SoundIoInStream *instream);
+SOUNDIO_EXPORT enum SoundIoError soundio_instream_start(struct SoundIoInStream *instream);
 
 /// Call this function when you are ready to begin reading from the device
 /// buffer.
@@ -1138,7 +1138,7 @@ SOUNDIO_EXPORT int soundio_instream_start(struct SoundIoInStream *instream);
 /// * #SoundIoErrorIncompatibleDevice - in rare cases it might just now
 ///   be discovered that the device uses non-byte-aligned access, in which
 ///   case this error code is returned.
-SOUNDIO_EXPORT int soundio_instream_begin_read(struct SoundIoInStream *instream,
+SOUNDIO_EXPORT enum SoundIoError soundio_instream_begin_read(struct SoundIoInStream *instream,
         struct SoundIoChannelArea **areas, int *frame_count);
 /// This will drop all of the frames from when you called
 /// ::soundio_instream_begin_read.
@@ -1148,7 +1148,7 @@ SOUNDIO_EXPORT int soundio_instream_begin_read(struct SoundIoInStream *instream,
 ///
 /// Possible errors:
 /// * #SoundIoErrorStreaming
-SOUNDIO_EXPORT int soundio_instream_end_read(struct SoundIoInStream *instream);
+SOUNDIO_EXPORT enum SoundIoError soundio_instream_end_read(struct SoundIoInStream *instream);
 
 /// If the underyling device supports pausing, this pauses the stream and
 /// prevents SoundIoInStream::read_callback from being called. Otherwise this returns
@@ -1161,7 +1161,7 @@ SOUNDIO_EXPORT int soundio_instream_end_read(struct SoundIoInStream *instream);
 /// * #SoundIoErrorBackendDisconnected
 /// * #SoundIoErrorStreaming
 /// * #SoundIoErrorIncompatibleDevice - device does not support pausing/unpausing
-SOUNDIO_EXPORT int soundio_instream_pause(struct SoundIoInStream *instream, bool pause);
+SOUNDIO_EXPORT enum SoundIoError soundio_instream_pause(struct SoundIoInStream *instream, bool pause);
 
 /// Obtain the number of seconds that the next frame of sound being
 /// captured will take to arrive in the buffer, plus the amount of time that is
@@ -1171,7 +1171,7 @@ SOUNDIO_EXPORT int soundio_instream_pause(struct SoundIoInStream *instream, bool
 ///
 /// Possible errors:
 /// * #SoundIoErrorStreaming
-SOUNDIO_EXPORT int soundio_instream_get_latency(struct SoundIoInStream *instream,
+SOUNDIO_EXPORT enum SoundIoError soundio_instream_get_latency(struct SoundIoInStream *instream,
         double *out_latency);
 
 
diff --git a/src/alsa.c b/src/alsa.c
index 81a2fda..78dc2b9 100644
--- a/src/alsa.c
+++ b/src/alsa.c
@@ -1276,7 +1276,7 @@ static void instream_thread_run(void *arg) {
     }
 }
 
-static int outstream_open_alsa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
+static enum SoundIoError outstream_open_alsa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
     struct SoundIoOutStreamAlsa *osa = &os->backend_data.alsa;
     struct SoundIoOutStream *outstream = &os->pub;
     struct SoundIoDevice *device = outstream->device;
@@ -1439,13 +1439,13 @@ static int outstream_open_alsa(struct SoundIoPrivate *si, struct SoundIoOutStrea
     return 0;
 }
 
-static int outstream_start_alsa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
+static enum SoundIoError outstream_start_alsa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
     struct SoundIoOutStreamAlsa *osa = &os->backend_data.alsa;
     struct SoundIo *soundio = &si->pub;
 
     assert(!osa->thread);
 
-    int err;
+    enum SoundIoError err;
     SOUNDIO_ATOMIC_FLAG_TEST_AND_SET(osa->thread_exit_flag);
     if ((err = soundio_os_thread_create(outstream_thread_run, os, soundio->emit_rtprio_warning, &osa->thread)))
         return err;
@@ -1453,7 +1453,7 @@ static int outstream_start_alsa(struct SoundIoPrivate *si, struct SoundIoOutStre
     return 0;
 }
 
-static int outstream_begin_write_alsa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os,
+static enum SoundIoError outstream_begin_write_alsa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os,
         struct SoundIoChannelArea **out_areas, int *frame_count)
 {
     *out_areas = NULL;
@@ -1504,7 +1504,7 @@ static int outstream_begin_write_alsa(struct SoundIoPrivate *si, struct SoundIoO
     return 0;
 }
 
-static int outstream_end_write_alsa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
+static enum SoundIoError outstream_end_write_alsa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
     struct SoundIoOutStreamAlsa *osa = &os->backend_data.alsa;
     struct SoundIoOutStream *outstream = &os->pub;
 
@@ -1531,7 +1531,7 @@ static int outstream_end_write_alsa(struct SoundIoPrivate *si, struct SoundIoOut
     return 0;
 }
 
-static int outstream_clear_buffer_alsa(struct SoundIoPrivate *si,
+static enum SoundIoError outstream_clear_buffer_alsa(struct SoundIoPrivate *si,
         struct SoundIoOutStreamPrivate *os)
 {
     struct SoundIoOutStreamAlsa *osa = &os->backend_data.alsa;
@@ -1539,7 +1539,7 @@ static int outstream_clear_buffer_alsa(struct SoundIoPrivate *si,
     return 0;
 }
 
-static int outstream_pause_alsa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os, bool pause) {
+static enum SoundIoError outstream_pause_alsa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os, bool pause) {
     if (!si)
         return SoundIoErrorInvalid;
 
@@ -1560,7 +1560,7 @@ static int outstream_pause_alsa(struct SoundIoPrivate *si, struct SoundIoOutStre
     return 0;
 }
 
-static int outstream_get_latency_alsa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os,
+static enum SoundIoError outstream_get_latency_alsa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os,
         double *out_latency)
 {
     struct SoundIoOutStream *outstream = &os->pub;
@@ -1600,7 +1600,7 @@ static void instream_destroy_alsa(struct SoundIoPrivate *si, struct SoundIoInStr
     isa->sample_buffer = NULL;
 }
 
-static int instream_open_alsa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
+static enum SoundIoError instream_open_alsa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
     struct SoundIoInStreamAlsa *isa = &is->backend_data.alsa;
     struct SoundIoInStream *instream = &is->pub;
     struct SoundIoDevice *device = instream->device;
@@ -1741,14 +1741,14 @@ static int instream_open_alsa(struct SoundIoPrivate *si, struct SoundIoInStreamP
     return 0;
 }
 
-static int instream_start_alsa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
+static enum SoundIoError instream_start_alsa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
     struct SoundIoInStreamAlsa *isa = &is->backend_data.alsa;
     struct SoundIo *soundio = &si->pub;
 
     assert(!isa->thread);
 
     SOUNDIO_ATOMIC_FLAG_TEST_AND_SET(isa->thread_exit_flag);
-    int err;
+    enum SoundIoError err;
     if ((err = soundio_os_thread_create(instream_thread_run, is, soundio->emit_rtprio_warning, &isa->thread))) {
         instream_destroy_alsa(si, is);
         return err;
@@ -1757,7 +1757,7 @@ static int instream_start_alsa(struct SoundIoPrivate *si, struct SoundIoInStream
     return 0;
 }
 
-static int instream_begin_read_alsa(struct SoundIoPrivate *si,
+static enum SoundIoError instream_begin_read_alsa(struct SoundIoPrivate *si,
         struct SoundIoInStreamPrivate *is, struct SoundIoChannelArea **out_areas, int *frame_count)
 {
     *out_areas = NULL;
@@ -1822,7 +1822,7 @@ static int instream_begin_read_alsa(struct SoundIoPrivate *si,
     return 0;
 }
 
-static int instream_end_read_alsa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
+static enum SoundIoError instream_end_read_alsa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
     struct SoundIoInStreamAlsa *isa = &is->backend_data.alsa;
 
     if (isa->access == SND_PCM_ACCESS_RW_INTERLEAVED) {
@@ -1841,7 +1841,7 @@ static int instream_end_read_alsa(struct SoundIoPrivate *si, struct SoundIoInStr
     return 0;
 }
 
-static int instream_pause_alsa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is, bool pause) {
+static enum SoundIoError instream_pause_alsa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is, bool pause) {
     struct SoundIoInStreamAlsa *isa = &is->backend_data.alsa;
 
     if (isa->is_paused == pause)
@@ -1855,7 +1855,7 @@ static int instream_pause_alsa(struct SoundIoPrivate *si, struct SoundIoInStream
     return 0;
 }
 
-static int instream_get_latency_alsa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is,
+static enum SoundIoError instream_get_latency_alsa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is,
         double *out_latency)
 {
     struct SoundIoInStream *instream = &is->pub;
@@ -1871,7 +1871,7 @@ static int instream_get_latency_alsa(struct SoundIoPrivate *si, struct SoundIoIn
     return 0;
 }
 
-int soundio_alsa_init(struct SoundIoPrivate *si) {
+enum SoundIoError soundio_alsa_init(struct SoundIoPrivate *si) {
     struct SoundIoAlsa *sia = &si->backend_data.alsa;
     int err;
 
diff --git a/src/alsa.h b/src/alsa.h
index e2b1764..6954141 100644
--- a/src/alsa.h
+++ b/src/alsa.h
@@ -16,7 +16,7 @@
 #include <alsa/asoundlib.h>
 
 struct SoundIoPrivate;
-int soundio_alsa_init(struct SoundIoPrivate *si);
+enum SoundIoError soundio_alsa_init(struct SoundIoPrivate *si);
 
 struct SoundIoDeviceAlsa { int make_the_struct_not_empty; };
 
diff --git a/src/coreaudio.c b/src/coreaudio.c
index a483b53..8b32078 100644
--- a/src/coreaudio.c
+++ b/src/coreaudio.c
@@ -946,7 +946,7 @@ static int set_ca_desc(enum SoundIoFormat fmt, AudioStreamBasicDescription *desc
     return 0;
 }
 
-static int outstream_open_ca(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
+static enum SoundIoError outstream_open_ca(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
     struct SoundIoOutStreamCoreAudio *osca = &os->backend_data.coreaudio;
     struct SoundIoOutStream *outstream = &os->pub;
     struct SoundIoDevice *device = outstream->device;
@@ -1046,7 +1046,7 @@ static int outstream_open_ca(struct SoundIoPrivate *si, struct SoundIoOutStreamP
     return 0;
 }
 
-static int outstream_pause_ca(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os, bool pause) {
+static enum SoundIoError outstream_pause_ca(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os, bool pause) {
     struct SoundIoOutStreamCoreAudio *osca = &os->backend_data.coreaudio;
     OSStatus os_err;
     if (pause) {
@@ -1062,11 +1062,11 @@ static int outstream_pause_ca(struct SoundIoPrivate *si, struct SoundIoOutStream
     return 0;
 }
 
-static int outstream_start_ca(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
+static enum SoundIoError outstream_start_ca(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
     return outstream_pause_ca(si, os, false);
 }
 
-static int outstream_begin_write_ca(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os,
+static enum SoundIoError outstream_begin_write_ca(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os,
         struct SoundIoChannelArea **out_areas, int *frame_count)
 {
     struct SoundIoOutStream *outstream = &os->pub;
@@ -1091,7 +1091,7 @@ static int outstream_begin_write_ca(struct SoundIoPrivate *si, struct SoundIoOut
     return 0;
 }
 
-static int outstream_end_write_ca(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
+static enum SoundIoError outstream_end_write_ca(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
     struct SoundIoOutStreamCoreAudio *osca = &os->backend_data.coreaudio;
     osca->buffer_index += 1;
     osca->frames_left -= osca->write_frame_count;
@@ -1099,11 +1099,11 @@ static int outstream_end_write_ca(struct SoundIoPrivate *si, struct SoundIoOutSt
     return 0;
 }
 
-static int outstream_clear_buffer_ca(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
+static enum SoundIoError outstream_clear_buffer_ca(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
     return SoundIoErrorIncompatibleBackend;
 }
 
-static int outstream_get_latency_ca(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os,
+static enum SoundIoError outstream_get_latency_ca(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os,
         double *out_latency)
 {
     struct SoundIoOutStreamCoreAudio *osca = &os->backend_data.coreaudio;
@@ -1188,7 +1188,7 @@ static OSStatus read_callback_ca(void *userdata, AudioUnitRenderActionFlags *io_
     return noErr;
 }
 
-static int instream_open_ca(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
+static enum SoundIoError instream_open_ca(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
     struct SoundIoInStreamCoreAudio *isca = &is->backend_data.coreaudio;
     struct SoundIoInStream *instream = &is->pub;
     struct SoundIoDevice *device = instream->device;
@@ -1332,7 +1332,7 @@ static int instream_open_ca(struct SoundIoPrivate *si, struct SoundIoInStreamPri
     return 0;
 }
 
-static int instream_pause_ca(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is, bool pause) {
+static enum SoundIoError instream_pause_ca(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is, bool pause) {
     struct SoundIoInStreamCoreAudio *isca = &is->backend_data.coreaudio;
     OSStatus os_err;
     if (pause) {
@@ -1348,11 +1348,11 @@ static int instream_pause_ca(struct SoundIoPrivate *si, struct SoundIoInStreamPr
     return 0;
 }
 
-static int instream_start_ca(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
+static enum SoundIoError instream_start_ca(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
     return instream_pause_ca(si, is, false);
 }
 
-static int instream_begin_read_ca(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is,
+static enum SoundIoError instream_begin_read_ca(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is,
         struct SoundIoChannelArea **out_areas, int *frame_count)
 {
     struct SoundIoInStreamCoreAudio *isca = &is->backend_data.coreaudio;
@@ -1365,13 +1365,13 @@ static int instream_begin_read_ca(struct SoundIoPrivate *si, struct SoundIoInStr
     return 0;
 }
 
-static int instream_end_read_ca(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
+static enum SoundIoError instream_end_read_ca(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
     struct SoundIoInStreamCoreAudio *isca = &is->backend_data.coreaudio;
     isca->frames_left = 0;
     return 0;
 }
 
-static int instream_get_latency_ca(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is,
+static enum SoundIoError instream_get_latency_ca(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is,
         double *out_latency)
 {
     struct SoundIoInStreamCoreAudio *isca = &is->backend_data.coreaudio;
@@ -1380,7 +1380,7 @@ static int instream_get_latency_ca(struct SoundIoPrivate *si, struct SoundIoInSt
 }
 
 
-int soundio_coreaudio_init(struct SoundIoPrivate *si) {
+enum SoundIoError soundio_coreaudio_init(struct SoundIoPrivate *si) {
     struct SoundIoCoreAudio *sica = &si->backend_data.coreaudio;
     int err;
 
diff --git a/src/coreaudio.h b/src/coreaudio.h
index 784a71c..8b80f74 100644
--- a/src/coreaudio.h
+++ b/src/coreaudio.h
@@ -17,7 +17,7 @@
 #include <AudioUnit/AudioUnit.h>
 
 struct SoundIoPrivate;
-int soundio_coreaudio_init(struct SoundIoPrivate *si);
+enum SoundIoError soundio_coreaudio_init(struct SoundIoPrivate *si);
 
 struct SoundIoDeviceCoreAudio {
     AudioDeviceID device_id;
diff --git a/src/dummy.c b/src/dummy.c
index 5e0ff61..22aedd2 100644
--- a/src/dummy.c
+++ b/src/dummy.c
@@ -172,7 +172,7 @@ static void outstream_destroy_dummy(struct SoundIoPrivate *si, struct SoundIoOut
     soundio_ring_buffer_deinit(&osd->ring_buffer);
 }
 
-static int outstream_open_dummy(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
+static enum SoundIoError outstream_open_dummy(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
     struct SoundIoOutStreamDummy *osd = &os->backend_data.dummy;
     struct SoundIoOutStream *outstream = &os->pub;
     struct SoundIoDevice *device = outstream->device;
@@ -187,7 +187,7 @@ static int outstream_open_dummy(struct SoundIoPrivate *si, struct SoundIoOutStre
 
     osd->period_duration = outstream->software_latency / 2.0;
 
-    int err;
+    enum SoundIoError err;
     int buffer_size = outstream->bytes_per_frame * outstream->sample_rate * outstream->software_latency;
     if ((err = soundio_ring_buffer_init(&osd->ring_buffer, buffer_size))) {
         outstream_destroy_dummy(si, os);
@@ -206,13 +206,15 @@ static int outstream_open_dummy(struct SoundIoPrivate *si, struct SoundIoOutStre
     return 0;
 }
 
-static int outstream_pause_dummy(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os, bool pause) {
+static enum SoundIoError outstream_pause_dummy(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os,
+        bool pause)
+{
     struct SoundIoOutStreamDummy *osd = &os->backend_data.dummy;
     SOUNDIO_ATOMIC_STORE(osd->pause_requested, pause);
-    return 0;
+    return SoundIoErrorNone;
 }
 
-static int outstream_start_dummy(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
+static enum SoundIoError outstream_start_dummy(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
     struct SoundIoOutStreamDummy *osd = &os->backend_data.dummy;
     struct SoundIo *soundio = &si->pub;
     assert(!osd->thread);
@@ -223,10 +225,10 @@ static int outstream_start_dummy(struct SoundIoPrivate *si, struct SoundIoOutStr
     {
         return err;
     }
-    return 0;
+    return SoundIoErrorNone;
 }
 
-static int outstream_begin_write_dummy(struct SoundIoPrivate *si,
+static enum SoundIoError outstream_begin_write_dummy(struct SoundIoPrivate *si,
         struct SoundIoOutStreamPrivate *os, struct SoundIoChannelArea **out_areas, int *frame_count)
 {
     struct SoundIoOutStream *outstream = &os->pub;
@@ -243,32 +245,32 @@ static int outstream_begin_write_dummy(struct SoundIoPrivate *si,
 
     osd->write_frame_count = *frame_count;
     *out_areas = osd->areas;
-    return 0;
+    return SoundIoErrorNone;
 }
 
-static int outstream_end_write_dummy(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
+static enum SoundIoError outstream_end_write_dummy(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
     struct SoundIoOutStreamDummy *osd = &os->backend_data.dummy;
     struct SoundIoOutStream *outstream = &os->pub;
     int byte_count = osd->write_frame_count * outstream->bytes_per_frame;
     soundio_ring_buffer_advance_write_ptr(&osd->ring_buffer, byte_count);
     osd->frames_left -= osd->write_frame_count;
-    return 0;
+    return SoundIoErrorNone;
 }
 
-static int outstream_clear_buffer_dummy(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
+static enum SoundIoError outstream_clear_buffer_dummy(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
     struct SoundIoOutStreamDummy *osd = &os->backend_data.dummy;
     SOUNDIO_ATOMIC_FLAG_CLEAR(osd->clear_buffer_flag);
     soundio_os_cond_signal(osd->cond, NULL);
-    return 0;
+    return SoundIoErrorNone;
 }
 
-static int outstream_get_latency_dummy(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os, double *out_latency) {
+static enum SoundIoError outstream_get_latency_dummy(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os, double *out_latency) {
     struct SoundIoOutStream *outstream = &os->pub;
     struct SoundIoOutStreamDummy *osd = &os->backend_data.dummy;
     int fill_bytes = soundio_ring_buffer_fill_count(&osd->ring_buffer);
 
     *out_latency = (fill_bytes / outstream->bytes_per_frame) / (double)outstream->sample_rate;
-    return 0;
+    return SoundIoErrorNone;
 }
 
 static void instream_destroy_dummy(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
@@ -286,7 +288,7 @@ static void instream_destroy_dummy(struct SoundIoPrivate *si, struct SoundIoInSt
     soundio_ring_buffer_deinit(&isd->ring_buffer);
 }
 
-static int instream_open_dummy(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
+static enum SoundIoError instream_open_dummy(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
     struct SoundIoInStreamDummy *isd = &is->backend_data.dummy;
     struct SoundIoInStream *instream = &is->pub;
     struct SoundIoDevice *device = instream->device;
@@ -321,13 +323,13 @@ static int instream_open_dummy(struct SoundIoPrivate *si, struct SoundIoInStream
     return 0;
 }
 
-static int instream_pause_dummy(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is, bool pause) {
+static enum SoundIoError instream_pause_dummy(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is, bool pause) {
     struct SoundIoInStreamDummy *isd = &is->backend_data.dummy;
     SOUNDIO_ATOMIC_STORE(isd->pause_requested, pause);
     return 0;
 }
 
-static int instream_start_dummy(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
+static enum SoundIoError instream_start_dummy(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
     struct SoundIoInStreamDummy *isd = &is->backend_data.dummy;
     struct SoundIo *soundio = &si->pub;
     assert(!isd->thread);
@@ -341,7 +343,7 @@ static int instream_start_dummy(struct SoundIoPrivate *si, struct SoundIoInStrea
     return 0;
 }
 
-static int instream_begin_read_dummy(struct SoundIoPrivate *si,
+static enum SoundIoError instream_begin_read_dummy(struct SoundIoPrivate *si,
         struct SoundIoInStreamPrivate *is, struct SoundIoChannelArea **out_areas, int *frame_count)
 {
     struct SoundIoInStream *instream = &is->pub;
@@ -361,7 +363,7 @@ static int instream_begin_read_dummy(struct SoundIoPrivate *si,
     return 0;
 }
 
-static int instream_end_read_dummy(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
+static enum SoundIoError instream_end_read_dummy(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
     struct SoundIoInStreamDummy *isd = &is->backend_data.dummy;
     struct SoundIoInStream *instream = &is->pub;
     int byte_count = isd->read_frame_count * instream->bytes_per_frame;
@@ -370,7 +372,7 @@ static int instream_end_read_dummy(struct SoundIoPrivate *si, struct SoundIoInSt
     return 0;
 }
 
-static int instream_get_latency_dummy(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is, double *out_latency) {
+static enum SoundIoError instream_get_latency_dummy(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is, double *out_latency) {
     struct SoundIoInStream *instream = &is->pub;
     struct SoundIoInStreamDummy *osd = &is->backend_data.dummy;
     int fill_bytes = soundio_ring_buffer_fill_count(&osd->ring_buffer);
@@ -379,7 +381,7 @@ static int instream_get_latency_dummy(struct SoundIoPrivate *si, struct SoundIoI
     return 0;
 }
 
-static int set_all_device_formats(struct SoundIoDevice *device) {
+static enum SoundIoError set_all_device_formats(struct SoundIoDevice *device) {
     device->format_count = 22;
     device->formats = ALLOCATE(enum SoundIoFormat, device->format_count);
     if (!device->formats)
@@ -419,7 +421,7 @@ static void set_all_device_sample_rates(struct SoundIoDevice *device) {
     device->sample_rates[0].max = SOUNDIO_MAX_SAMPLE_RATE;
 }
 
-static int set_all_device_channel_layouts(struct SoundIoDevice *device) {
+static enum SoundIoError set_all_device_channel_layouts(struct SoundIoDevice *device) {
     device->layout_count = soundio_channel_layout_builtin_count();
     device->layouts = ALLOCATE(struct SoundIoChannelLayout, device->layout_count);
     if (!device->layouts)
@@ -429,7 +431,7 @@ static int set_all_device_channel_layouts(struct SoundIoDevice *device) {
     return 0;
 }
 
-int soundio_dummy_init(struct SoundIoPrivate *si) {
+enum SoundIoError soundio_dummy_init(struct SoundIoPrivate *si) {
     struct SoundIo *soundio = &si->pub;
     struct SoundIoDummy *sid = &si->backend_data.dummy;
 
diff --git a/src/dummy.h b/src/dummy.h
index d50d12e..2ed01a6 100644
--- a/src/dummy.h
+++ b/src/dummy.h
@@ -14,7 +14,7 @@
 #include "atomics.h"
 
 struct SoundIoPrivate;
-int soundio_dummy_init(struct SoundIoPrivate *si);
+enum SoundIoError soundio_dummy_init(struct SoundIoPrivate *si);
 
 struct SoundIoDummy {
     struct SoundIoOsMutex *mutex;
diff --git a/src/jack.c b/src/jack.c
index c56bf15..fff441f 100644
--- a/src/jack.c
+++ b/src/jack.c
@@ -425,7 +425,7 @@ static inline jack_nframes_t nframes_max(jack_nframes_t a, jack_nframes_t b) {
     return (a >= b) ? a : b;
 }
 
-static int outstream_open_jack(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
+static enum SoundIoError outstream_open_jack(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
     struct SoundIoJack *sij = &si->backend_data.jack;
     struct SoundIoOutStreamJack *osj = &os->backend_data.jack;
     struct SoundIoOutStream *outstream = &os->pub;
@@ -454,7 +454,7 @@ static int outstream_open_jack(struct SoundIoPrivate *si, struct SoundIoOutStrea
         return SoundIoErrorOpeningDevice;
     }
 
-    int err;
+    enum SoundIoError err;
     if ((err = jack_set_process_callback(osj->client, outstream_process_callback, os))) {
         outstream_destroy_jack(si, os);
         return SoundIoErrorOpeningDevice;
@@ -521,7 +521,7 @@ static int outstream_open_jack(struct SoundIoPrivate *si, struct SoundIoOutStrea
     return 0;
 }
 
-static int outstream_pause_jack(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os, bool pause) {
+static enum SoundIoError outstream_pause_jack(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os, bool pause) {
     struct SoundIoJack *sij = &si->backend_data.jack;
 
     if (sij->is_shutdown)
@@ -530,11 +530,11 @@ static int outstream_pause_jack(struct SoundIoPrivate *si, struct SoundIoOutStre
     return SoundIoErrorIncompatibleBackend;
 }
 
-static int outstream_start_jack(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
+static enum SoundIoError outstream_start_jack(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
     struct SoundIoOutStreamJack *osj = &os->backend_data.jack;
     struct SoundIoOutStream *outstream = &os->pub;
     struct SoundIoJack *sij = &si->backend_data.jack;
-    int err;
+    enum SoundIoError err;
 
     if (sij->is_shutdown)
         return SoundIoErrorBackendDisconnected;
@@ -556,7 +556,7 @@ static int outstream_start_jack(struct SoundIoPrivate *si, struct SoundIoOutStre
     return 0;
 }
 
-static int outstream_begin_write_jack(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os,
+static enum SoundIoError outstream_begin_write_jack(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os,
         struct SoundIoChannelArea **out_areas, int *frame_count)
 {
     struct SoundIoOutStreamJack *osj = &os->backend_data.jack;
@@ -569,17 +569,17 @@ static int outstream_begin_write_jack(struct SoundIoPrivate *si, struct SoundIoO
     return 0;
 }
 
-static int outstream_end_write_jack(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
+static enum SoundIoError outstream_end_write_jack(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
     struct SoundIoOutStreamJack *osj = &os->backend_data.jack;
     osj->frames_left = 0;
     return 0;
 }
 
-static int outstream_clear_buffer_jack(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
+static enum SoundIoError outstream_clear_buffer_jack(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
     return SoundIoErrorIncompatibleBackend;
 }
 
-static int outstream_get_latency_jack(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os,
+static enum SoundIoError outstream_get_latency_jack(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os,
         double *out_latency)
 {
     struct SoundIoOutStreamJack *osj = &os->backend_data.jack;
@@ -646,7 +646,7 @@ static int instream_process_callback(jack_nframes_t nframes, void *arg) {
     return 0;
 }
 
-static int instream_open_jack(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
+static enum SoundIoError instream_open_jack(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
     struct SoundIoInStream *instream = &is->pub;
     struct SoundIoInStreamJack *isj = &is->backend_data.jack;
     struct SoundIoJack *sij = &si->backend_data.jack;
@@ -675,7 +675,7 @@ static int instream_open_jack(struct SoundIoPrivate *si, struct SoundIoInStreamP
         return SoundIoErrorOpeningDevice;
     }
 
-    int err;
+    enum SoundIoError err;
     if ((err = jack_set_process_callback(isj->client, instream_process_callback, is))) {
         instream_destroy_jack(si, is);
         return SoundIoErrorOpeningDevice;
@@ -741,7 +741,7 @@ static int instream_open_jack(struct SoundIoPrivate *si, struct SoundIoInStreamP
     return 0;
 }
 
-static int instream_pause_jack(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is, bool pause) {
+static enum SoundIoError instream_pause_jack(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is, bool pause) {
     struct SoundIoJack *sij = &si->backend_data.jack;
 
     if (sij->is_shutdown)
@@ -750,11 +750,11 @@ static int instream_pause_jack(struct SoundIoPrivate *si, struct SoundIoInStream
     return SoundIoErrorIncompatibleBackend;
 }
 
-static int instream_start_jack(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
+static enum SoundIoError instream_start_jack(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
     struct SoundIoInStreamJack *isj = &is->backend_data.jack;
     struct SoundIoInStream *instream = &is->pub;
     struct SoundIoJack *sij = &si->backend_data.jack;
-    int err;
+    enum SoundIoError err;
 
     if (sij->is_shutdown)
         return SoundIoErrorBackendDisconnected;
@@ -776,7 +776,7 @@ static int instream_start_jack(struct SoundIoPrivate *si, struct SoundIoInStream
     return 0;
 }
 
-static int instream_begin_read_jack(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is,
+static enum SoundIoError instream_begin_read_jack(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is,
         struct SoundIoChannelArea **out_areas, int *frame_count)
 {
     struct SoundIoInStreamJack *isj = &is->backend_data.jack;
@@ -789,13 +789,13 @@ static int instream_begin_read_jack(struct SoundIoPrivate *si, struct SoundIoInS
     return 0;
 }
 
-static int instream_end_read_jack(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
+static enum SoundIoError instream_end_read_jack(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
     struct SoundIoInStreamJack *isj = &is->backend_data.jack;
     isj->frames_left = 0;
     return 0;
 }
 
-static int instream_get_latency_jack(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is,
+static enum SoundIoError instream_get_latency_jack(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is,
         double *out_latency)
 {
     struct SoundIoInStreamJack *isj = &is->backend_data.jack;
@@ -865,7 +865,7 @@ static void destroy_jack(struct SoundIoPrivate *si) {
         soundio_os_mutex_destroy(sij->mutex);
 }
 
-int soundio_jack_init(struct SoundIoPrivate *si) {
+enum SoundIoError soundio_jack_init(struct SoundIoPrivate *si) {
     struct SoundIoJack *sij = &si->backend_data.jack;
     struct SoundIo *soundio = &si->pub;
 
diff --git a/src/jack.h b/src/jack.h
index e96cf9b..d960939 100644
--- a/src/jack.h
+++ b/src/jack.h
@@ -20,7 +20,7 @@
 #pragma GCC diagnostic pop
 
 struct SoundIoPrivate;
-int soundio_jack_init(struct SoundIoPrivate *si);
+enum SoundIoError soundio_jack_init(struct SoundIoPrivate *si);
 
 struct SoundIoDeviceJackPort {
     char *full_name;
diff --git a/src/pulseaudio.c b/src/pulseaudio.c
index 3f1bb6a..339018b 100644
--- a/src/pulseaudio.c
+++ b/src/pulseaudio.c
@@ -661,7 +661,7 @@ static void timing_update_callback(pa_stream *stream, int success, void *userdat
     pa_threaded_mainloop_signal(sipa->main_loop, 0);
 }
 
-static int outstream_open_pa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
+static enum SoundIoError outstream_open_pa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
     struct SoundIoOutStreamPulseAudio *ospa = &os->backend_data.pulseaudio;
     struct SoundIoOutStream *outstream = &os->pub;
 
@@ -737,7 +737,7 @@ static int outstream_open_pa(struct SoundIoPrivate *si, struct SoundIoOutStreamP
     return 0;
 }
 
-static int outstream_start_pa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
+static enum SoundIoError outstream_start_pa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
     struct SoundIoOutStream *outstream = &os->pub;
     struct SoundIoPulseAudio *sipa = &si->backend_data.pulseaudio;
     struct SoundIoOutStreamPulseAudio *ospa = &os->backend_data.pulseaudio;
@@ -763,7 +763,7 @@ static int outstream_start_pa(struct SoundIoPrivate *si, struct SoundIoOutStream
     return 0;
 }
 
-static int outstream_begin_write_pa(struct SoundIoPrivate *si,
+static enum SoundIoError outstream_begin_write_pa(struct SoundIoPrivate *si,
         struct SoundIoOutStreamPrivate *os, struct SoundIoChannelArea **out_areas, int *frame_count)
 {
     struct SoundIoOutStream *outstream = &os->pub;
@@ -785,7 +785,7 @@ static int outstream_begin_write_pa(struct SoundIoPrivate *si,
     return 0;
 }
 
-static int outstream_end_write_pa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
+static enum SoundIoError outstream_end_write_pa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os) {
     struct SoundIoOutStreamPulseAudio *ospa = &os->backend_data.pulseaudio;
     pa_stream *stream = ospa->stream;
 
@@ -796,7 +796,7 @@ static int outstream_end_write_pa(struct SoundIoPrivate *si, struct SoundIoOutSt
     return 0;
 }
 
-static int outstream_clear_buffer_pa(struct SoundIoPrivate *si,
+static enum SoundIoError outstream_clear_buffer_pa(struct SoundIoPrivate *si,
         struct SoundIoOutStreamPrivate *os)
 {
     struct SoundIoOutStreamPulseAudio *ospa = &os->backend_data.pulseaudio;
@@ -804,7 +804,7 @@ static int outstream_clear_buffer_pa(struct SoundIoPrivate *si,
     return 0;
 }
 
-static int outstream_pause_pa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os, bool pause) {
+static enum SoundIoError outstream_pause_pa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os, bool pause) {
     struct SoundIoOutStreamPulseAudio *ospa = &os->backend_data.pulseaudio;
     struct SoundIoPulseAudio *sipa = &si->backend_data.pulseaudio;
 
@@ -828,7 +828,7 @@ static int outstream_pause_pa(struct SoundIoPrivate *si, struct SoundIoOutStream
     return 0;
 }
 
-static int outstream_get_latency_pa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os, double *out_latency) {
+static enum SoundIoError outstream_get_latency_pa(struct SoundIoPrivate *si, struct SoundIoOutStreamPrivate *os, double *out_latency) {
     struct SoundIoOutStreamPulseAudio *ospa = &os->backend_data.pulseaudio;
 
     int err;
@@ -890,7 +890,7 @@ static void instream_destroy_pa(struct SoundIoPrivate *si, struct SoundIoInStrea
     }
 }
 
-static int instream_open_pa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
+static enum SoundIoError instream_open_pa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
     struct SoundIoInStreamPulseAudio *ispa = &is->backend_data.pulseaudio;
     struct SoundIoInStream *instream = &is->pub;
 
@@ -941,7 +941,7 @@ static int instream_open_pa(struct SoundIoPrivate *si, struct SoundIoInStreamPri
     return 0;
 }
 
-static int instream_start_pa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
+static enum SoundIoError instream_start_pa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
     struct SoundIoInStream *instream = &is->pub;
     struct SoundIoInStreamPulseAudio *ispa = &is->backend_data.pulseaudio;
     struct SoundIoPulseAudio *sipa = &si->backend_data.pulseaudio;
@@ -971,7 +971,7 @@ static int instream_start_pa(struct SoundIoPrivate *si, struct SoundIoInStreamPr
     return 0;
 }
 
-static int instream_begin_read_pa(struct SoundIoPrivate *si,
+static enum SoundIoError instream_begin_read_pa(struct SoundIoPrivate *si,
         struct SoundIoInStreamPrivate *is, struct SoundIoChannelArea **out_areas, int *frame_count)
 {
     struct SoundIoInStream *instream = &is->pub;
@@ -1007,7 +1007,7 @@ static int instream_begin_read_pa(struct SoundIoPrivate *si,
     return 0;
 }
 
-static int instream_end_read_pa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
+static enum SoundIoError instream_end_read_pa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
     struct SoundIoInStream *instream = &is->pub;
     struct SoundIoInStreamPulseAudio *ispa = &is->backend_data.pulseaudio;
     pa_stream *stream = ispa->stream;
@@ -1032,7 +1032,7 @@ static int instream_end_read_pa(struct SoundIoPrivate *si, struct SoundIoInStrea
     return 0;
 }
 
-static int instream_pause_pa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is, bool pause) {
+static enum SoundIoError instream_pause_pa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is, bool pause) {
     struct SoundIoInStreamPulseAudio *ispa = &is->backend_data.pulseaudio;
     struct SoundIoPulseAudio *sipa = &si->backend_data.pulseaudio;
 
@@ -1054,7 +1054,7 @@ static int instream_pause_pa(struct SoundIoPrivate *si, struct SoundIoInStreamPr
     return 0;
 }
 
-static int instream_get_latency_pa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is, double *out_latency) {
+static enum SoundIoError instream_get_latency_pa(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is, double *out_latency) {
     struct SoundIoInStreamPulseAudio *ispa = &is->backend_data.pulseaudio;
 
     int err;
@@ -1067,7 +1067,7 @@ static int instream_get_latency_pa(struct SoundIoPrivate *si, struct SoundIoInSt
     return 0;
 }
 
-int soundio_pulseaudio_init(struct SoundIoPrivate *si) {
+enum SoundIoError soundio_pulseaudio_init(struct SoundIoPrivate *si) {
     struct SoundIo *soundio = &si->pub;
     struct SoundIoPulseAudio *sipa = &si->backend_data.pulseaudio;
 
diff --git a/src/pulseaudio.h b/src/pulseaudio.h
index a216e26..0ae2bef 100644
--- a/src/pulseaudio.h
+++ b/src/pulseaudio.h
@@ -14,7 +14,7 @@
 #include <pulse/pulseaudio.h>
 
 struct SoundIoPrivate;
-int soundio_pulseaudio_init(struct SoundIoPrivate *si);
+enum SoundIoError soundio_pulseaudio_init(struct SoundIoPrivate *si);
 
 struct SoundIoDevicePulseAudio { int make_the_struct_not_empty; };
 
diff --git a/src/soundio.c b/src/soundio.c
index 866841d..3de5fab 100644
--- a/src/soundio.c
+++ b/src/soundio.c
@@ -33,7 +33,7 @@ static const enum SoundIoBackend available_backends[] = {
     SoundIoBackendDummy,
 };
 
-typedef int (*backend_init_t)(struct SoundIoPrivate *);
+typedef enum SoundIoError (*backend_init_t)(struct SoundIoPrivate *);
 static backend_init_t backend_init_fns[] = {
     NULL, // None backend
 
@@ -73,8 +73,8 @@ static backend_init_t backend_init_fns[] = {
 SOUNDIO_MAKE_LIST_DEF(struct SoundIoDevice*, SoundIoListDevicePtr, SOUNDIO_LIST_NOT_STATIC)
 SOUNDIO_MAKE_LIST_DEF(struct SoundIoSampleRateRange, SoundIoListSampleRateRange, SOUNDIO_LIST_NOT_STATIC)
 
-const char *soundio_strerror(int error) {
-    switch ((enum SoundIoError)error) {
+const char *soundio_strerror(enum SoundIoError error) {
+    switch (error) {
         case SoundIoErrorNone: return "(no error)";
         case SoundIoErrorNoMem: return "out of memory";
         case SoundIoErrorInitAudioBackend: return "unable to initialize audio backend";
@@ -181,7 +181,7 @@ void soundio_destroy(struct SoundIo *soundio) {
 static void do_nothing_cb(struct SoundIo *soundio) { }
 static void default_msg_callback(const char *msg) { }
 
-static void default_backend_disconnect_cb(struct SoundIo *soundio, int err) {
+static void default_backend_disconnect_cb(struct SoundIo *soundio, enum SoundIoError err) {
     soundio_panic("libsoundio: backend disconnected: %s", soundio_strerror(err));
 }
 
@@ -195,7 +195,7 @@ static void default_emit_rtprio_warning(void) {
 }
 
 struct SoundIo *soundio_create(void) {
-    int err;
+    enum SoundIoError err;
     if ((err = soundio_os_init()))
         return NULL;
     struct SoundIoPrivate *si = ALLOCATE(struct SoundIoPrivate, 1);
@@ -212,7 +212,7 @@ struct SoundIo *soundio_create(void) {
     return soundio;
 }
 
-int soundio_connect(struct SoundIo *soundio) {
+enum SoundIoError soundio_connect(struct SoundIo *soundio) {
     int err = 0;
 
     for (int i = 0; i < ARRAY_LENGTH(available_backends); i += 1) {
@@ -227,7 +227,7 @@ int soundio_connect(struct SoundIo *soundio) {
     return err;
 }
 
-int soundio_connect_backend(struct SoundIo *soundio, enum SoundIoBackend backend) {
+enum SoundIoError soundio_connect_backend(struct SoundIo *soundio, enum SoundIoBackend backend) {
     struct SoundIoPrivate *si = (struct SoundIoPrivate *)soundio;
 
     if (soundio->current_backend)
@@ -236,7 +236,7 @@ int soundio_connect_backend(struct SoundIo *soundio, enum SoundIoBackend backend
     if (backend <= 0 || backend > SoundIoBackendDummy)
         return SoundIoErrorInvalid;
 
-    int (*fn)(struct SoundIoPrivate *) = backend_init_fns[backend];
+    enum SoundIoError (*fn)(struct SoundIoPrivate *) = backend_init_fns[backend];
 
     if (!fn)
         return SoundIoErrorBackendUnavailable;
@@ -446,7 +446,7 @@ void soundio_force_device_scan(struct SoundIo *soundio) {
     si->force_device_scan(si);
 }
 
-int soundio_outstream_begin_write(struct SoundIoOutStream *outstream,
+enum SoundIoError soundio_outstream_begin_write(struct SoundIoOutStream *outstream,
         struct SoundIoChannelArea **areas, int *frame_count)
 {
     struct SoundIo *soundio = outstream->device->soundio;
@@ -457,14 +457,14 @@ int soundio_outstream_begin_write(struct SoundIoOutStream *outstream,
     return si->outstream_begin_write(si, os, areas, frame_count);
 }
 
-int soundio_outstream_end_write(struct SoundIoOutStream *outstream) {
+enum SoundIoError soundio_outstream_end_write(struct SoundIoOutStream *outstream) {
     struct SoundIo *soundio = outstream->device->soundio;
     struct SoundIoPrivate *si = (struct SoundIoPrivate *)soundio;
     struct SoundIoOutStreamPrivate *os = (struct SoundIoOutStreamPrivate *)outstream;
     return si->outstream_end_write(si, os);
 }
 
-static void default_outstream_error_callback(struct SoundIoOutStream *os, int err) {
+static void default_outstream_error_callback(struct SoundIoOutStream *os, enum SoundIoError err) {
     soundio_panic("libsoundio: %s", soundio_strerror(err));
 }
 
@@ -488,7 +488,7 @@ struct SoundIoOutStream *soundio_outstream_create(struct SoundIoDevice *device)
     return outstream;
 }
 
-int soundio_outstream_open(struct SoundIoOutStream *outstream) {
+enum SoundIoError soundio_outstream_open(struct SoundIoOutStream *outstream) {
     struct SoundIoDevice *device = outstream->device;
 
     if (device->aim != SoundIoDeviceAimOutput)
@@ -540,35 +540,35 @@ void soundio_outstream_destroy(struct SoundIoOutStream *outstream) {
     free(os);
 }
 
-int soundio_outstream_start(struct SoundIoOutStream *outstream) {
+enum SoundIoError soundio_outstream_start(struct SoundIoOutStream *outstream) {
     struct SoundIo *soundio = outstream->device->soundio;
     struct SoundIoPrivate *si = (struct SoundIoPrivate *)soundio;
     struct SoundIoOutStreamPrivate *os = (struct SoundIoOutStreamPrivate *)outstream;
     return si->outstream_start(si, os);
 }
 
-int soundio_outstream_pause(struct SoundIoOutStream *outstream, bool pause) {
+enum SoundIoError soundio_outstream_pause(struct SoundIoOutStream *outstream, bool pause) {
     struct SoundIo *soundio = outstream->device->soundio;
     struct SoundIoPrivate *si = (struct SoundIoPrivate *)soundio;
     struct SoundIoOutStreamPrivate *os = (struct SoundIoOutStreamPrivate *)outstream;
     return si->outstream_pause(si, os, pause);
 }
 
-int soundio_outstream_clear_buffer(struct SoundIoOutStream *outstream) {
+enum SoundIoError soundio_outstream_clear_buffer(struct SoundIoOutStream *outstream) {
     struct SoundIo *soundio = outstream->device->soundio;
     struct SoundIoPrivate *si = (struct SoundIoPrivate *)soundio;
     struct SoundIoOutStreamPrivate *os = (struct SoundIoOutStreamPrivate *)outstream;
     return si->outstream_clear_buffer(si, os);
 }
 
-int soundio_outstream_get_latency(struct SoundIoOutStream *outstream, double *out_latency) {
+enum SoundIoError soundio_outstream_get_latency(struct SoundIoOutStream *outstream, double *out_latency) {
     struct SoundIo *soundio = outstream->device->soundio;
     struct SoundIoPrivate *si = (struct SoundIoPrivate *)soundio;
     struct SoundIoOutStreamPrivate *os = (struct SoundIoOutStreamPrivate *)outstream;
     return si->outstream_get_latency(si, os, out_latency);
 }
 
-static void default_instream_error_callback(struct SoundIoInStream *is, int err) {
+static void default_instream_error_callback(struct SoundIoInStream *is, enum SoundIoError err) {
     soundio_panic("libsoundio: %s", soundio_strerror(err));
 }
 
@@ -592,7 +592,7 @@ struct SoundIoInStream *soundio_instream_create(struct SoundIoDevice *device) {
     return instream;
 }
 
-int soundio_instream_open(struct SoundIoInStream *instream) {
+enum SoundIoError soundio_instream_open(struct SoundIoInStream *instream) {
     struct SoundIoDevice *device = instream->device;
     if (device->aim != SoundIoDeviceAimInput)
         return SoundIoErrorInvalid;
@@ -628,7 +628,7 @@ int soundio_instream_open(struct SoundIoInStream *instream) {
     return si->instream_open(si, is);
 }
 
-int soundio_instream_start(struct SoundIoInStream *instream) {
+enum SoundIoError soundio_instream_start(struct SoundIoInStream *instream) {
     struct SoundIo *soundio = instream->device->soundio;
     struct SoundIoPrivate *si = (struct SoundIoPrivate *)soundio;
     struct SoundIoInStreamPrivate *is = (struct SoundIoInStreamPrivate *)instream;
@@ -650,14 +650,14 @@ void soundio_instream_destroy(struct SoundIoInStream *instream) {
     free(is);
 }
 
-int soundio_instream_pause(struct SoundIoInStream *instream, bool pause) {
+enum SoundIoError soundio_instream_pause(struct SoundIoInStream *instream, bool pause) {
     struct SoundIo *soundio = instream->device->soundio;
     struct SoundIoPrivate *si = (struct SoundIoPrivate *)soundio;
     struct SoundIoInStreamPrivate *is = (struct SoundIoInStreamPrivate *)instream;
     return si->instream_pause(si, is, pause);
 }
 
-int soundio_instream_begin_read(struct SoundIoInStream *instream,
+enum SoundIoError soundio_instream_begin_read(struct SoundIoInStream *instream,
         struct SoundIoChannelArea **areas, int *frame_count)
 {
     struct SoundIo *soundio = instream->device->soundio;
@@ -666,14 +666,14 @@ int soundio_instream_begin_read(struct SoundIoInStream *instream,
     return si->instream_begin_read(si, is, areas, frame_count);
 }
 
-int soundio_instream_end_read(struct SoundIoInStream *instream) {
+enum SoundIoError soundio_instream_end_read(struct SoundIoInStream *instream) {
     struct SoundIo *soundio = instream->device->soundio;
     struct SoundIoPrivate *si = (struct SoundIoPrivate *)soundio;
     struct SoundIoInStreamPrivate *is = (struct SoundIoInStreamPrivate *)instream;
     return si->instream_end_read(si, is);
 }
 
-int soundio_instream_get_latency(struct SoundIoInStream *instream, double *out_latency) {
+enum SoundIoError soundio_instream_get_latency(struct SoundIoInStream *instream, double *out_latency) {
     struct SoundIo *soundio = instream->device->soundio;
     struct SoundIoPrivate *si = (struct SoundIoPrivate *)soundio;
     struct SoundIoInStreamPrivate *is = (struct SoundIoInStreamPrivate *)instream;
diff --git a/src/soundio_private.h b/src/soundio_private.h
index 213b36f..1e1ab4a 100644
--- a/src/soundio_private.h
+++ b/src/soundio_private.h
@@ -143,25 +143,25 @@ struct SoundIoPrivate {
     void (*wakeup)(struct SoundIoPrivate *);
     void (*force_device_scan)(struct SoundIoPrivate *);
 
-    int (*outstream_open)(struct SoundIoPrivate *, struct SoundIoOutStreamPrivate *);
+    enum SoundIoError (*outstream_open)(struct SoundIoPrivate *, struct SoundIoOutStreamPrivate *);
     void (*outstream_destroy)(struct SoundIoPrivate *, struct SoundIoOutStreamPrivate *);
-    int (*outstream_start)(struct SoundIoPrivate *, struct SoundIoOutStreamPrivate *);
-    int (*outstream_begin_write)(struct SoundIoPrivate *, struct SoundIoOutStreamPrivate *,
+    enum SoundIoError (*outstream_start)(struct SoundIoPrivate *, struct SoundIoOutStreamPrivate *);
+    enum SoundIoError (*outstream_begin_write)(struct SoundIoPrivate *, struct SoundIoOutStreamPrivate *,
             struct SoundIoChannelArea **out_areas, int *out_frame_count);
-    int (*outstream_end_write)(struct SoundIoPrivate *, struct SoundIoOutStreamPrivate *);
-    int (*outstream_clear_buffer)(struct SoundIoPrivate *, struct SoundIoOutStreamPrivate *);
-    int (*outstream_pause)(struct SoundIoPrivate *, struct SoundIoOutStreamPrivate *, bool pause);
-    int (*outstream_get_latency)(struct SoundIoPrivate *, struct SoundIoOutStreamPrivate *, double *out_latency);
+    enum SoundIoError (*outstream_end_write)(struct SoundIoPrivate *, struct SoundIoOutStreamPrivate *);
+    enum SoundIoError (*outstream_clear_buffer)(struct SoundIoPrivate *, struct SoundIoOutStreamPrivate *);
+    enum SoundIoError (*outstream_pause)(struct SoundIoPrivate *, struct SoundIoOutStreamPrivate *, bool pause);
+    enum SoundIoError (*outstream_get_latency)(struct SoundIoPrivate *, struct SoundIoOutStreamPrivate *, double *out_latency);
 
 
-    int (*instream_open)(struct SoundIoPrivate *, struct SoundIoInStreamPrivate *);
+    enum SoundIoError (*instream_open)(struct SoundIoPrivate *, struct SoundIoInStreamPrivate *);
     void (*instream_destroy)(struct SoundIoPrivate *, struct SoundIoInStreamPrivate *);
-    int (*instream_start)(struct SoundIoPrivate *, struct SoundIoInStreamPrivate *);
-    int (*instream_begin_read)(struct SoundIoPrivate *, struct SoundIoInStreamPrivate *,
+    enum SoundIoError (*instream_start)(struct SoundIoPrivate *, struct SoundIoInStreamPrivate *);
+    enum SoundIoError (*instream_begin_read)(struct SoundIoPrivate *, struct SoundIoInStreamPrivate *,
             struct SoundIoChannelArea **out_areas, int *out_frame_count);
-    int (*instream_end_read)(struct SoundIoPrivate *, struct SoundIoInStreamPrivate *);
-    int (*instream_pause)(struct SoundIoPrivate *, struct SoundIoInStreamPrivate *, bool pause);
-    int (*instream_get_latency)(struct SoundIoPrivate *, struct SoundIoInStreamPrivate *, double *out_latency);
+    enum SoundIoError (*instream_end_read)(struct SoundIoPrivate *, struct SoundIoInStreamPrivate *);
+    enum SoundIoError (*instream_pause)(struct SoundIoPrivate *, struct SoundIoInStreamPrivate *, bool pause);
+    enum SoundIoError (*instream_get_latency)(struct SoundIoPrivate *, struct SoundIoInStreamPrivate *, double *out_latency);
 
     union SoundIoBackendData backend_data;
 };
diff --git a/test/backend_disconnect_recover.c b/test/backend_disconnect_recover.c
index 046a150..8f04191 100644
--- a/test/backend_disconnect_recover.c
+++ b/test/backend_disconnect_recover.c
@@ -38,7 +38,7 @@ static enum SoundIoBackend backend = SoundIoBackendNone;
 
 static bool severed = false;
 
-static void on_backend_disconnect(struct SoundIo *soundio, int err) {
+static void on_backend_disconnect(struct SoundIo *soundio, enum SoundIoError err) {
     fprintf(stderr, "OK backend disconnected with '%s'.\n", soundio_strerror(err));
     severed = true;
 }
diff --git a/test/unit_tests.c b/test/unit_tests.c
index 2a39282..9ba33f4 100644
--- a/test/unit_tests.c
+++ b/test/unit_tests.c
@@ -26,7 +26,7 @@ static void test_os_get_time(void) {
 }
 
 static void write_callback(struct SoundIoOutStream *device, int frame_count_min, int frame_count_max) { }
-static void error_callback(struct SoundIoOutStream *device, int err) { }
+static void error_callback(struct SoundIoOutStream *device, enum SoundIoError err) { }
 
 static void test_create_outstream(void) {
     struct SoundIo *soundio = soundio_create();