diff --git a/.gitignore b/.gitignore
index 04029d7..a2bcaac 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 build/
-build-win/
+build-win32/
+build-win64/
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9cb03b7..c81d811 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -99,7 +99,6 @@ set(LIBSOUNDIO_SOURCES
 set(CONFIGURE_OUT_FILE "${CMAKE_BINARY_DIR}/config.h")
 set(LIBSOUNDIO_HEADERS
     "${CMAKE_SOURCE_DIR}/soundio/soundio.h"
-    "${CMAKE_SOURCE_DIR}/soundio/os.h"
     ${CONFIGURE_OUT_FILE}
 )
 
@@ -163,7 +162,7 @@ set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -Werror -pedantic")
 set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -Werror -pedantic")
 
 
-set(LIB_CFLAGS "-std=c++11 -fno-exceptions -fno-rtti -Wall -Werror=strict-prototypes -Werror=old-style-definition -Werror=missing-prototypes")
+set(LIB_CFLAGS "-std=c++11 -fno-exceptions -fno-rtti -fvisibility=hidden -Wall -Werror=strict-prototypes -Werror=old-style-definition -Werror=missing-prototypes")
 set(EXAMPLE_CFLAGS "-std=c99 -Wall")
 set(EXAMPLE_INCLUDES "${CMAKE_SOURCE_DIR}/src")
 set(TEST_CFLAGS "${LIB_CFLAGS} -fprofile-arcs -ftest-coverage")
diff --git a/README.md b/README.md
index cf9fd46..a9a74a1 100644
--- a/README.md
+++ b/README.md
@@ -225,19 +225,26 @@ packages necessary on your system. Then somewhere on your file system:
 ```
 git clone https://github.com/mxe/mxe
 cd mxe
-make gcc
+make MXE_TARGETS='x86_64-w64-mingw32.static i686-w64-mingw32.static' gcc
 ```
 
 Then in the libsoundio source directory (replace "/path/to/mxe" with the
 appropriate path):
 
 ```
-mkdir build-win
-cd build-win
+mkdir build-win32
+cd build-win32
 cmake .. -DCMAKE_TOOLCHAIN_FILE=/path/to/mxe/usr/i686-w64-mingw32.static/share/cmake/mxe-conf.cmake
 make
 ```
 
+```
+mkdir build-win64
+cd build-win64
+cmake .. -DCMAKE_TOOLCHAIN_FILE=/path/to/mxe/usr/x86_64-w64-mingw32.static/share/cmake/mxe-conf.cmake
+make
+```
+
 #### Running the Tests
 
 ```
@@ -257,8 +264,9 @@ view `coverage/index.html` in a browser.
 ## Roadmap
 
  0. implement WASAPI (Windows) backend, get examples working
-    - sine wave
+    - sine wave (raw device)
     - microphone
+    - set display name of output stream
  0. Make sure PulseAudio can handle refresh devices crashing before
     block_until_have_devices
  0. Integrate into libgroove and test with Groove Basin
@@ -283,8 +291,6 @@ view `coverage/index.html` in a browser.
     - make sure every function which can return an error documents which errors
       it can return
  0. use a documentation generator and host the docs somewhere
- 0. -fvisibility=hidden and then explicitly export stuff, or
-    explicitly make the unexported stuff private
  0. add len arguments to APIs that have char *
     - replace strdup with `soundio_str_dupe`
  0. Support PulseAudio proplist properties for main context and streams
@@ -298,6 +304,10 @@ view `coverage/index.html` in a browser.
  0. In ALSA do we need to wake up the poll when destroying the in or out stream?
  0. Detect PulseAudio server going offline and emit `on_backend_disconnect`.
  0. Add [sndio](http://www.sndio.org/) backend to support OpenBSD.
+ 0. Support for stream icon.
+    - PulseAudio: XDG icon name
+    - WASAPI: path to .exe, .dll, or .ico
+    - CoreAudio: CFURLRef image file
 
 ## Planned Uses for libsoundio
 
diff --git a/soundio/soundio.h b/soundio/soundio.h
index e5065d9..dfd601c 100644
--- a/soundio/soundio.h
+++ b/soundio/soundio.h
@@ -12,8 +12,19 @@
 #include <stdbool.h>
 
 #ifdef __cplusplus
-extern "C"
-{
+#define SOUNDIO_EXTERN_C extern "C"
+#else
+#define SOUNDIO_EXTERN_C
+#endif
+
+#if defined(_WIN32)
+#if defined(SOUNDIO_BUILDING_LIBRARY)
+#define SOUNDIO_EXPORT SOUNDIO_EXTERN_C __declspec(dllexport)
+#else
+#define SOUNDIO_EXPORT SOUNDIO_EXTERN_C __declspec(dllimport)
+#endif
+#else
+#define SOUNDIO_EXPORT SOUNDIO_EXTERN_C __attribute__((visibility ("default")))
 #endif
 
 enum SoundIoError {
@@ -532,29 +543,29 @@ struct SoundIoInStream {
 
 // Create a SoundIo context. You may create multiple instances of this to
 // connect to multiple backends.
-struct SoundIo * soundio_create(void);
-void soundio_destroy(struct SoundIo *soundio);
+SOUNDIO_EXPORT struct SoundIo * soundio_create(void);
+SOUNDIO_EXPORT void soundio_destroy(struct SoundIo *soundio);
 
 
 // This is a convenience function you could implement yourself if you wanted
 // to. It tries `soundio_connect_backend` on all available backends in order.
-int soundio_connect(struct SoundIo *soundio);
+SOUNDIO_EXPORT int soundio_connect(struct SoundIo *soundio);
 // Instead of calling `soundio_connect` you may call this function to try a
 // specific backend.
-int soundio_connect_backend(struct SoundIo *soundio, enum SoundIoBackend backend);
-void soundio_disconnect(struct SoundIo *soundio);
+SOUNDIO_EXPORT int soundio_connect_backend(struct SoundIo *soundio, enum SoundIoBackend backend);
+SOUNDIO_EXPORT void soundio_disconnect(struct SoundIo *soundio);
 
-const char *soundio_strerror(int error);
-const char *soundio_backend_name(enum SoundIoBackend backend);
+SOUNDIO_EXPORT const char *soundio_strerror(int error);
+SOUNDIO_EXPORT const char *soundio_backend_name(enum SoundIoBackend backend);
 
 // Returns the number of available backends.
-int soundio_backend_count(struct SoundIo *soundio);
+SOUNDIO_EXPORT int soundio_backend_count(struct SoundIo *soundio);
 // get the available backend at the specified index
 // (0 <= index < `soundio_backend_count`)
-enum SoundIoBackend soundio_get_backend(struct SoundIo *soundio, int index);
+SOUNDIO_EXPORT enum SoundIoBackend soundio_get_backend(struct SoundIo *soundio, int index);
 
 // Returns whether libsoundio was compiled with `backend`.
-bool soundio_have_backend(enum SoundIoBackend backend);
+SOUNDIO_EXPORT bool soundio_have_backend(enum SoundIoBackend backend);
 
 // When you call this, the `on_devices_change` and `on_events_signal` callbacks
 // might be called. This is the only time those callbacks will be called.
@@ -566,14 +577,14 @@ bool soundio_have_backend(enum SoundIoBackend backend);
 // * `soundio_get_output_device`
 // * `soundio_default_input_device_index`
 // * `soundio_default_output_device_index`
-void soundio_flush_events(struct SoundIo *soundio);
+SOUNDIO_EXPORT void soundio_flush_events(struct SoundIo *soundio);
 
 // This function calls `soundio_flush_events` then blocks until another event
 // is ready or you call `soundio_wakeup`. Be ready for spurious wakeups.
-void soundio_wait_events(struct SoundIo *soundio);
+SOUNDIO_EXPORT void soundio_wait_events(struct SoundIo *soundio);
 
 // Makes `soundio_wait_events` stop blocking.
-void soundio_wakeup(struct SoundIo *soundio);
+SOUNDIO_EXPORT void soundio_wakeup(struct SoundIo *soundio);
 
 
 
@@ -581,44 +592,44 @@ void soundio_wakeup(struct SoundIo *soundio);
 
 // Returns whether the channel count field and each channel id matches in
 // the supplied channel layouts.
-bool soundio_channel_layout_equal(
+SOUNDIO_EXPORT bool soundio_channel_layout_equal(
         const struct SoundIoChannelLayout *a,
         const struct SoundIoChannelLayout *b);
 
-const char *soundio_get_channel_name(enum SoundIoChannelId id);
+SOUNDIO_EXPORT const char *soundio_get_channel_name(enum SoundIoChannelId id);
 // Given UTF-8 encoded text which is the name of a channel such as
 // "Front Left", "FL", or "front-left", return the corresponding
 // SoundIoChannelId. Returns SoundIoChannelIdInvalid for no match.
-enum SoundIoChannelId soundio_parse_channel_id(const char *str, int str_len);
+SOUNDIO_EXPORT enum SoundIoChannelId soundio_parse_channel_id(const char *str, int str_len);
 
-int soundio_channel_layout_builtin_count(void);
-const struct SoundIoChannelLayout *soundio_channel_layout_get_builtin(int index);
+SOUNDIO_EXPORT int soundio_channel_layout_builtin_count(void);
+SOUNDIO_EXPORT const struct SoundIoChannelLayout *soundio_channel_layout_get_builtin(int index);
 
 // Get the default builtin channel layout for the given number of channels.
-const struct SoundIoChannelLayout *soundio_channel_layout_get_default(int channel_count);
+SOUNDIO_EXPORT const struct SoundIoChannelLayout *soundio_channel_layout_get_default(int channel_count);
 
-int soundio_channel_layout_find_channel(
+SOUNDIO_EXPORT int soundio_channel_layout_find_channel(
         const struct SoundIoChannelLayout *layout, enum SoundIoChannelId channel);
 
 // Populates the name field of layout if it matches a builtin one.
 // returns whether it found a match
-bool soundio_channel_layout_detect_builtin(struct SoundIoChannelLayout *layout);
+SOUNDIO_EXPORT bool soundio_channel_layout_detect_builtin(struct SoundIoChannelLayout *layout);
 
 // Iterates over preferred_layouts. Returns the first channel layout in
 // preferred_layouts which matches one of the channel layouts in
 // available_layouts. Returns NULL if none matches.
-const struct SoundIoChannelLayout *soundio_best_matching_channel_layout(
+SOUNDIO_EXPORT const struct SoundIoChannelLayout *soundio_best_matching_channel_layout(
         const struct SoundIoChannelLayout *preferred_layouts, int preferred_layout_count,
         const struct SoundIoChannelLayout *available_layouts, int available_layout_count);
 
 // Sorts by channel count, descending.
-void soundio_sort_channel_layouts(struct SoundIoChannelLayout *layouts, int layout_count);
+SOUNDIO_EXPORT void soundio_sort_channel_layouts(struct SoundIoChannelLayout *layouts, int layout_count);
 
 
 // Sample Formats
 
 // Returns -1 on invalid format.
-int soundio_get_bytes_per_sample(enum SoundIoFormat format);
+SOUNDIO_EXPORT int soundio_get_bytes_per_sample(enum SoundIoFormat format);
 
 static inline int soundio_get_bytes_per_frame(enum SoundIoFormat format, int channel_count) {
     return soundio_get_bytes_per_sample(format) * channel_count;
@@ -631,7 +642,7 @@ static inline int soundio_get_bytes_per_second(enum SoundIoFormat format,
     return soundio_get_bytes_per_frame(format, channel_count) * sample_rate;
 }
 
-const char * soundio_format_string(enum SoundIoFormat format);
+SOUNDIO_EXPORT const char * soundio_format_string(enum SoundIoFormat format);
 
 
 
@@ -647,60 +658,60 @@ const char * soundio_format_string(enum SoundIoFormat format);
 
 // Get the number of input devices.
 // Returns -1 if you never called `soundio_flush_events`.
-int soundio_input_device_count(struct SoundIo *soundio);
+SOUNDIO_EXPORT int soundio_input_device_count(struct SoundIo *soundio);
 // Get the number of output devices.
 // Returns -1 if you never called `soundio_flush_events`.
-int soundio_output_device_count(struct SoundIo *soundio);
+SOUNDIO_EXPORT int soundio_output_device_count(struct SoundIo *soundio);
 
 // Always returns a device. Call soundio_device_unref when done.
 // `index` must be 0 <= index < soundio_input_device_count
 // Returns NULL if you never called `soundio_flush_events` or if you provide
 // invalid parameter values.
-struct SoundIoDevice *soundio_get_input_device(struct SoundIo *soundio, int index);
+SOUNDIO_EXPORT struct SoundIoDevice *soundio_get_input_device(struct SoundIo *soundio, int index);
 // Always returns a device. Call soundio_device_unref when done.
 // `index` must be 0 <= index < soundio_output_device_count
 // Returns NULL if you never called `soundio_flush_events` or if you provide
 // invalid parameter values.
-struct SoundIoDevice *soundio_get_output_device(struct SoundIo *soundio, int index);
+SOUNDIO_EXPORT struct SoundIoDevice *soundio_get_output_device(struct SoundIo *soundio, int index);
 
 // returns the index of the default input device
 // returns -1 if there are no devices or if you never called
 // `soundio_flush_events`.
-int soundio_default_input_device_index(struct SoundIo *soundio);
+SOUNDIO_EXPORT int soundio_default_input_device_index(struct SoundIo *soundio);
 
 // returns the index of the default output device
 // returns -1 if there are no devices or if you never called
 // `soundio_flush_events`.
-int soundio_default_output_device_index(struct SoundIo *soundio);
+SOUNDIO_EXPORT int soundio_default_output_device_index(struct SoundIo *soundio);
 
-void soundio_device_ref(struct SoundIoDevice *device);
-void soundio_device_unref(struct SoundIoDevice *device);
+SOUNDIO_EXPORT void soundio_device_ref(struct SoundIoDevice *device);
+SOUNDIO_EXPORT void soundio_device_unref(struct SoundIoDevice *device);
 
-bool soundio_device_equal(
+SOUNDIO_EXPORT bool soundio_device_equal(
         const struct SoundIoDevice *a,
         const struct SoundIoDevice *b);
 
 // Sorts channel layouts by channel count, descending.
-void soundio_device_sort_channel_layouts(struct SoundIoDevice *device);
+SOUNDIO_EXPORT void soundio_device_sort_channel_layouts(struct SoundIoDevice *device);
 
 // Convenience function. Returns whether `format` is included in the device's
 // supported formats.
-bool soundio_device_supports_format(struct SoundIoDevice *device,
+SOUNDIO_EXPORT bool soundio_device_supports_format(struct SoundIoDevice *device,
         enum SoundIoFormat format);
 
 // Convenience function. Returns whether `layout` is included in the device's
 // supported channel layouts.
-bool soundio_device_supports_layout(struct SoundIoDevice *device,
+SOUNDIO_EXPORT bool soundio_device_supports_layout(struct SoundIoDevice *device,
         const struct SoundIoChannelLayout *layout);
 
 // Convenience function. Returns whether `sample_rate` is included in the
 // device's supported sample rates.
-bool soundio_device_supports_sample_rate(struct SoundIoDevice *device,
+SOUNDIO_EXPORT bool soundio_device_supports_sample_rate(struct SoundIoDevice *device,
         int sample_rate);
 
 // Convenience function. Returns the available sample rate nearest to
 // `sample_rate`, rounding up.
-int soundio_device_nearest_sample_rate(struct SoundIoDevice *device,
+SOUNDIO_EXPORT int soundio_device_nearest_sample_rate(struct SoundIoDevice *device,
         int sample_rate);
 
 
@@ -708,17 +719,17 @@ int soundio_device_nearest_sample_rate(struct SoundIoDevice *device,
 // Output Streams
 // Allocates memory and sets defaults. Next you should fill out the struct fields
 // and then call `soundio_outstream_open`.
-struct SoundIoOutStream *soundio_outstream_create(struct SoundIoDevice *device);
+SOUNDIO_EXPORT struct SoundIoOutStream *soundio_outstream_create(struct SoundIoDevice *device);
 // You may not call this function from the `write_callback` thread context.
-void soundio_outstream_destroy(struct SoundIoOutStream *outstream);
+SOUNDIO_EXPORT void soundio_outstream_destroy(struct SoundIoOutStream *outstream);
 
 // After you call this function, `software_latency` is set to the correct
 // value.
 // The next thing to do is call `soundio_instream_start`.
-int soundio_outstream_open(struct SoundIoOutStream *outstream);
+SOUNDIO_EXPORT int soundio_outstream_open(struct SoundIoOutStream *outstream);
 
 // After you call this function, `write_callback` will be called.
-int soundio_outstream_start(struct SoundIoOutStream *outstream);
+SOUNDIO_EXPORT int 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.
@@ -738,23 +749,23 @@ int soundio_outstream_start(struct SoundIoOutStream *outstream);
 // If you call this function with `frame_count` less than the `frame_count_min`
 // parameter from `write_callback` it returns SoundIoErrorInvalid.
 // If this function returns an error, do not call `soundio_outstream_end_write`.
-int soundio_outstream_begin_write(struct SoundIoOutStream *outstream,
+SOUNDIO_EXPORT int soundio_outstream_begin_write(struct SoundIoOutStream *outstream,
         struct SoundIoChannelArea **areas, int *frame_count);
 
 // Commits the write that you began with `soundio_outstream_begin_write`.
 // You must call this function only from the `write_callback` thread context.
 // This function might return `SoundIoErrorUnderflow` but don't count on it.
-int soundio_outstream_end_write(struct SoundIoOutStream *outstream);
+SOUNDIO_EXPORT int soundio_outstream_end_write(struct SoundIoOutStream *outstream);
 
 // Clears the output stream buffer.
 // You must call this function only from the `write_callback` thread context.
-int soundio_outstream_clear_buffer(struct SoundIoOutStream *outstream);
+SOUNDIO_EXPORT int soundio_outstream_clear_buffer(struct SoundIoOutStream *outstream);
 
 // If the underyling device supports pausing, this pauses the stream and
 // prevents `write_callback` from being called. Otherwise this returns
 // `SoundIoErrorIncompatibleDevice`.
 // You must call this function only from the `write_callback` thread context.
-int soundio_outstream_pause(struct SoundIoOutStream *outstream, bool pause);
+SOUNDIO_EXPORT int soundio_outstream_pause(struct SoundIoOutStream *outstream, bool pause);
 
 
 
@@ -762,17 +773,17 @@ int soundio_outstream_pause(struct SoundIoOutStream *outstream, bool pause);
 // Input Streams
 // Allocates memory and sets defaults. Next you should fill out the struct fields
 // and then call `soundio_instream_open`.
-struct SoundIoInStream *soundio_instream_create(struct SoundIoDevice *device);
+SOUNDIO_EXPORT struct SoundIoInStream *soundio_instream_create(struct SoundIoDevice *device);
 // You may not call this function from `read_callback`.
-void soundio_instream_destroy(struct SoundIoInStream *instream);
+SOUNDIO_EXPORT void soundio_instream_destroy(struct SoundIoInStream *instream);
 
 // After you call this function, `software_latency` is set to the correct
 // value.
 // The next thing to do is call `soundio_instream_start`.
-int soundio_instream_open(struct SoundIoInStream *instream);
+SOUNDIO_EXPORT int soundio_instream_open(struct SoundIoInStream *instream);
 
 // After you call this function, `read_callback` will be called.
-int soundio_instream_start(struct SoundIoInStream *instream);
+SOUNDIO_EXPORT int soundio_instream_start(struct SoundIoInStream *instream);
 
 // Call this function when you are ready to begin reading from the device
 // buffer.
@@ -796,51 +807,46 @@ int soundio_instream_start(struct SoundIoInStream *instream);
 // and move the read index forward. `soundio_instream_end_read` should not be
 // called if the buffer is empty (`frame_count` == 0), but it should be called
 // if there is a hole.
-int soundio_instream_begin_read(struct SoundIoInStream *instream,
+SOUNDIO_EXPORT int 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`.
 // You must call this function only from the `read_callback` thread context.
 // You must call this function only after a successful call to
 // `soundio_instream_begin_read`.
-int soundio_instream_end_read(struct SoundIoInStream *instream);
+SOUNDIO_EXPORT int soundio_instream_end_read(struct SoundIoInStream *instream);
 
 // If the underyling device supports pausing, this pauses the stream and
 // prevents `read_callback` from being called. Otherwise this returns
 // `SoundIoErrorIncompatibleDevice`.
 // You must call this function only from the `read_callback` thread context.
-int soundio_instream_pause(struct SoundIoInStream *instream, bool pause);
+SOUNDIO_EXPORT int soundio_instream_pause(struct SoundIoInStream *instream, bool pause);
 
 
 // Ring Buffer
 struct SoundIoRingBuffer;
 // `requested_capacity` in bytes.
-struct SoundIoRingBuffer *soundio_ring_buffer_create(struct SoundIo *soundio, int requested_capacity);
-void soundio_ring_buffer_destroy(struct SoundIoRingBuffer *ring_buffer);
-int soundio_ring_buffer_capacity(struct SoundIoRingBuffer *ring_buffer);
+SOUNDIO_EXPORT struct SoundIoRingBuffer *soundio_ring_buffer_create(struct SoundIo *soundio, int requested_capacity);
+SOUNDIO_EXPORT void soundio_ring_buffer_destroy(struct SoundIoRingBuffer *ring_buffer);
+SOUNDIO_EXPORT int soundio_ring_buffer_capacity(struct SoundIoRingBuffer *ring_buffer);
 
 // don't write more than capacity
-char *soundio_ring_buffer_write_ptr(struct SoundIoRingBuffer *ring_buffer);
+SOUNDIO_EXPORT char *soundio_ring_buffer_write_ptr(struct SoundIoRingBuffer *ring_buffer);
 // `count` in bytes.
-void soundio_ring_buffer_advance_write_ptr(struct SoundIoRingBuffer *ring_buffer, int count);
+SOUNDIO_EXPORT void soundio_ring_buffer_advance_write_ptr(struct SoundIoRingBuffer *ring_buffer, int count);
 
 // don't read more than capacity
-char *soundio_ring_buffer_read_ptr(struct SoundIoRingBuffer *ring_buffer);
+SOUNDIO_EXPORT char *soundio_ring_buffer_read_ptr(struct SoundIoRingBuffer *ring_buffer);
 // `count` in bytes.
-void soundio_ring_buffer_advance_read_ptr(struct SoundIoRingBuffer *ring_buffer, int count);
+SOUNDIO_EXPORT void soundio_ring_buffer_advance_read_ptr(struct SoundIoRingBuffer *ring_buffer, int count);
 
 // Returns how many bytes of the buffer is used, ready for reading.
-int soundio_ring_buffer_fill_count(struct SoundIoRingBuffer *ring_buffer);
+SOUNDIO_EXPORT int soundio_ring_buffer_fill_count(struct SoundIoRingBuffer *ring_buffer);
 
 // Returns how many bytes of the buffer is free, ready for writing.
-int soundio_ring_buffer_free_count(struct SoundIoRingBuffer *ring_buffer);
+SOUNDIO_EXPORT int soundio_ring_buffer_free_count(struct SoundIoRingBuffer *ring_buffer);
 
 // Must be called by the writer.
-void soundio_ring_buffer_clear(struct SoundIoRingBuffer *ring_buffer);
-
-
-#ifdef __cplusplus
-}
-#endif
+SOUNDIO_EXPORT void soundio_ring_buffer_clear(struct SoundIoRingBuffer *ring_buffer);
 
 #endif
diff --git a/src/alsa.hpp b/src/alsa.hpp
index baf7009..bac9ea8 100644
--- a/src/alsa.hpp
+++ b/src/alsa.hpp
@@ -8,8 +8,8 @@
 #ifndef SOUNDIO_ALSA_HPP
 #define SOUNDIO_ALSA_HPP
 
-#include "soundio/soundio.h"
-#include "soundio/os.h"
+#include "soundio_private.h"
+#include "os.h"
 #include "atomics.hpp"
 
 #include <alsa/asoundlib.h>
diff --git a/src/coreaudio.hpp b/src/coreaudio.hpp
index 45df501..ff3c988 100644
--- a/src/coreaudio.hpp
+++ b/src/coreaudio.hpp
@@ -8,8 +8,8 @@
 #ifndef SOUNDIO_COREAUDIO_HPP
 #define SOUNDIO_COREAUDIO_HPP
 
-#include "soundio/soundio.h"
-#include "soundio/os.h"
+#include "soundio_private.h"
+#include "os.h"
 #include "atomics.hpp"
 #include "list.hpp"
 
diff --git a/src/dummy.hpp b/src/dummy.hpp
index b4e40b4..118716c 100644
--- a/src/dummy.hpp
+++ b/src/dummy.hpp
@@ -8,8 +8,8 @@
 #ifndef SOUNDIO_DUMMY_HPP
 #define SOUNDIO_DUMMY_HPP
 
-#include "soundio/soundio.h"
-#include "soundio/os.h"
+#include "soundio_private.h"
+#include "os.h"
 #include "atomics.hpp"
 #include "ring_buffer.hpp"
 
diff --git a/src/jack.hpp b/src/jack.hpp
index f4783c5..4b6b17d 100644
--- a/src/jack.hpp
+++ b/src/jack.hpp
@@ -8,8 +8,8 @@
 #ifndef SOUNDIO_JACK_HPP
 #define SOUNDIO_JACK_HPP
 
-#include "soundio/soundio.h"
-#include "soundio/os.h"
+#include "soundio_private.h"
+#include "os.h"
 #include "atomics.hpp"
 
 #include <jack/jack.h>
diff --git a/src/list.hpp b/src/list.hpp
index 4f3dccd..31e0f27 100644
--- a/src/list.hpp
+++ b/src/list.hpp
@@ -9,7 +9,7 @@
 #define SOUNDIO_LIST_HPP
 
 #include "util.hpp"
-#include "soundio/soundio.h"
+#include "soundio_private.h"
 
 #include <assert.h>
 
diff --git a/src/os.cpp b/src/os.cpp
index 58ae7dd..2511bd5 100644
--- a/src/os.cpp
+++ b/src/os.cpp
@@ -5,8 +5,8 @@
  * See http://opensource.org/licenses/MIT
  */
 
-#include "soundio/os.h"
-#include "soundio/soundio.h"
+#include "os.h"
+#include "soundio_private.h"
 #include "util.hpp"
 #include "atomics.hpp"
 
diff --git a/soundio/os.h b/src/os.h
similarity index 96%
rename from soundio/os.h
rename to src/os.h
index da350b3..444a050 100644
--- a/soundio/os.h
+++ b/src/os.h
@@ -11,12 +11,6 @@
 #include <stdbool.h>
 #include <stddef.h>
 
-#ifdef __cplusplus
-extern "C"
-{
-#endif
-
-
 // safe to call from any thread(s) multiple times, but
 // must be called at least once before calling any other os functions
 // soundio_create calls this function.
@@ -69,8 +63,4 @@ struct SoundIoOsMirroredMemory {
 int soundio_os_init_mirrored_memory(struct SoundIoOsMirroredMemory *mem, size_t capacity);
 void soundio_os_deinit_mirrored_memory(struct SoundIoOsMirroredMemory *mem);
 
-#ifdef __cplusplus
-}
-#endif
-
 #endif
diff --git a/src/pulseaudio.hpp b/src/pulseaudio.hpp
index 8ea0c4a..46a72f2 100644
--- a/src/pulseaudio.hpp
+++ b/src/pulseaudio.hpp
@@ -8,7 +8,7 @@
 #ifndef SOUNDIO_PULSEAUDIO_HPP
 #define SOUNDIO_PULSEAUDIO_HPP
 
-#include "soundio/soundio.h"
+#include "soundio_private.h"
 #include "atomics.hpp"
 
 #include <pulse/pulseaudio.h>
diff --git a/src/ring_buffer.hpp b/src/ring_buffer.hpp
index 9ae7f4f..a34a322 100644
--- a/src/ring_buffer.hpp
+++ b/src/ring_buffer.hpp
@@ -9,7 +9,7 @@
 #define SOUNDIO_RING_BUFFER_HPP
 
 #include "atomics.hpp"
-#include "soundio/os.h"
+#include "os.h"
 
 struct SoundIoRingBuffer {
     SoundIoOsMirroredMemory mem;
diff --git a/src/soundio.cpp b/src/soundio.cpp
index cda86fe..f3cea3e 100644
--- a/src/soundio.cpp
+++ b/src/soundio.cpp
@@ -7,7 +7,7 @@
 
 #include "soundio.hpp"
 #include "util.hpp"
-#include "soundio/os.h"
+#include "os.h"
 #include "config.h"
 
 #include <string.h>
diff --git a/src/soundio.hpp b/src/soundio.hpp
index 40c6ea4..7378d93 100644
--- a/src/soundio.hpp
+++ b/src/soundio.hpp
@@ -8,7 +8,7 @@
 #ifndef SOUNDIO_SOUNDIO_HPP
 #define SOUNDIO_SOUNDIO_HPP
 
-#include "soundio/soundio.h"
+#include "soundio_private.h"
 #include "list.hpp"
 
 #ifdef SOUNDIO_HAVE_JACK
diff --git a/src/soundio_private.h b/src/soundio_private.h
new file mode 100644
index 0000000..1016a15
--- /dev/null
+++ b/src/soundio_private.h
@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2015 Andrew Kelley
+ *
+ * This file is part of libsoundio, which is MIT licensed.
+ * See http://opensource.org/licenses/MIT
+ */
+
+#ifndef SOUNDIO_SOUNDIO_PRIVATE_H
+#define SOUNDIO_SOUNDIO_PRIVATE_H
+
+// This exists for __declspec(dllexport) and __declspec(dllimport) to be
+// defined correctly without the library user having to do anything.
+#define SOUNDIO_BUILDING_LIBRARY
+#include "soundio/soundio.h"
+
+#endif
diff --git a/src/util.hpp b/src/util.hpp
index 06a8b6e..a34eae8 100644
--- a/src/util.hpp
+++ b/src/util.hpp
@@ -52,7 +52,7 @@ static inline bool soundio_streql(const char *str1, int str1_len, const char *st
 
 
 template <typename T, long n>
-constexpr long array_length(const T (&)[n]) {
+static constexpr long array_length(const T (&)[n]) {
     return n;
 }
 
diff --git a/src/wasapi.cpp b/src/wasapi.cpp
index dbc28ff..49bb14b 100644
--- a/src/wasapi.cpp
+++ b/src/wasapi.cpp
@@ -1176,8 +1176,11 @@ void outstream_shared_run(void *arg) {
             return;
         }
         osw->writable_frame_count = osw->buffer_frame_count - frames_used;
-        if (osw->writable_frame_count > 0)
+        if (osw->writable_frame_count > 0) {
+            if (frames_used == 0)
+                outstream->underflow_callback(outstream);
             outstream->write_callback(outstream, 0, osw->writable_frame_count);
+        }
     }
 }
 
diff --git a/src/wasapi.hpp b/src/wasapi.hpp
index 603212c..003ed47 100644
--- a/src/wasapi.hpp
+++ b/src/wasapi.hpp
@@ -8,8 +8,8 @@
 #ifndef SOUNDIO_WASAPI_HPP
 #define SOUNDIO_WASAPI_HPP
 
-#include "soundio/soundio.h"
-#include "soundio/os.h"
+#include "soundio_private.h"
+#include "os.h"
 #include "atomics.hpp"
 #include "list.hpp"
 
diff --git a/test/underflow.c b/test/underflow.c
index 9886a49..e469ccf 100644
--- a/test/underflow.c
+++ b/test/underflow.c
@@ -6,13 +6,13 @@
  */
 
 #include <soundio/soundio.h>
-#include <soundio/os.h>
 
 #include <stdio.h>
 #include <stdarg.h>
 #include <stdlib.h>
 #include <string.h>
 #include <math.h>
+#include <unistd.h>
 
 __attribute__ ((cold))
 __attribute__ ((noreturn))
@@ -34,7 +34,6 @@ static int usage(char *exe) {
 static const float PI = 3.1415926535f;
 static float seconds_offset = 0.0f;
 static bool caused_underflow = false;
-static struct SoundIoOsCond *cond = NULL;
 static struct SoundIo *soundio = NULL;
 static float seconds_end = 9.0f;
 
@@ -46,7 +45,7 @@ static void write_callback(struct SoundIoOutStream *outstream, int frame_count_m
 
     if (!caused_underflow && seconds_offset >= 3.0f) {
         caused_underflow = true;
-        soundio_os_cond_timed_wait(cond, NULL, 3.0);
+        sleep(3);
     }
 
     if (seconds_offset >= seconds_end) {
@@ -137,10 +136,6 @@ int main(int argc, char **argv) {
 
     fprintf(stderr, "Output device: %s\n", device->name);
 
-    cond = soundio_os_cond_create();
-    if (!cond)
-        panic("out of memory");
-
     struct SoundIoOutStream *outstream = soundio_outstream_create(device);
     outstream->format = SoundIoFormatFloat32NE;
     outstream->write_callback = write_callback;
@@ -160,7 +155,6 @@ int main(int argc, char **argv) {
 
     soundio_outstream_destroy(outstream);
     soundio_device_unref(device);
-    soundio_os_cond_destroy(cond);
     soundio_destroy(soundio);
     return 0;
 }
diff --git a/test/unit_tests.cpp b/test/unit_tests.cpp
index cd04bc4..45b1cb6 100644
--- a/test/unit_tests.cpp
+++ b/test/unit_tests.cpp
@@ -1,7 +1,7 @@
 #undef NDEBUG
 
 #include "soundio.hpp"
-#include "soundio/os.h"
+#include "os.h"
 #include "util.hpp"
 #include "atomics.hpp"