diff --git a/example/sio_list_devices.c b/example/sio_list_devices.c
index fc1f8a7..72a7f23 100644
--- a/example/sio_list_devices.c
+++ b/example/sio_list_devices.c
@@ -14,7 +14,7 @@
 // list or keep a watch on audio devices
 
 static int usage(char *exe) {
-    fprintf(stderr, "Usage: %s [--watch] [--dummy] [--alsa] [--pulseaudio] [--jack]\n", exe);
+    fprintf(stderr, "Usage: %s [--watch] [--backend dummy|alsa|pulseaudio|jack|coreaudio|wasapi]\n", exe);
     return 1;
 }
 
@@ -114,14 +114,30 @@ int main(int argc, char **argv) {
         char *arg = argv[i];
         if (strcmp("--watch", arg) == 0) {
             watch = true;
-        } else if (strcmp("--dummy", arg) == 0) {
-            backend = SoundIoBackendDummy;
-        } else if (strcmp("--alsa", arg) == 0) {
-            backend = SoundIoBackendAlsa;
-        } else if (strcmp("--pulseaudio", arg) == 0) {
-            backend = SoundIoBackendPulseAudio;
-        } else if (strcmp("--jack", arg) == 0) {
-            backend = SoundIoBackendJack;
+        } else if (arg[0] == '-' && arg[1] == '-') {
+            i += 1;
+            if (i >= argc) {
+                return usage(exe);
+            } else if (strcmp(arg, "--backend") == 0) {
+                if (strcmp("-dummy", argv[i]) == 0) {
+                    backend = SoundIoBackendDummy;
+                } else if (strcmp("alsa", argv[i]) == 0) {
+                    backend = SoundIoBackendAlsa;
+                } else if (strcmp("pulseaudio", argv[i]) == 0) {
+                    backend = SoundIoBackendPulseAudio;
+                } else if (strcmp("jack", argv[i]) == 0) {
+                    backend = SoundIoBackendJack;
+                } else if (strcmp("coreaudio", argv[i]) == 0) {
+                    backend = SoundIoBackendCoreAudio;
+                } else if (strcmp("wasapi", argv[i]) == 0) {
+                    backend = SoundIoBackendWasapi;
+                } else {
+                    fprintf(stderr, "Invalid backend: %s\n", argv[i]);
+                    return 1;
+                }
+            } else {
+                return usage(exe);
+            }
         } else {
             return usage(exe);
         }
diff --git a/src/soundio.cpp b/src/soundio.cpp
index f3cea3e..cafab58 100644
--- a/src/soundio.cpp
+++ b/src/soundio.cpp
@@ -375,8 +375,12 @@ void soundio_device_unref(struct SoundIoDevice *device) {
         free(device->id);
         free(device->name);
 
-        if (device->sample_rates != &dev->prealloc_sample_rate_range)
+        if (device->sample_rates != &dev->prealloc_sample_rate_range &&
+            device->sample_rates != dev->sample_rates.items)
+        {
             free(device->sample_rates);
+        }
+        dev->sample_rates.deinit();
 
         if (device->formats != &dev->prealloc_format)
             free(device->formats);
diff --git a/src/soundio.hpp b/src/soundio.hpp
index 7378d93..a894ebd 100644
--- a/src/soundio.hpp
+++ b/src/soundio.hpp
@@ -164,6 +164,7 @@ struct SoundIoDevicePrivate {
     SoundIoDeviceBackendData backend_data;
     void (*destruct)(SoundIoDevicePrivate *);
     SoundIoSampleRateRange prealloc_sample_rate_range;
+    SoundIoList<SoundIoSampleRateRange> sample_rates;
     SoundIoFormat prealloc_format;
 };
 
diff --git a/src/wasapi.cpp b/src/wasapi.cpp
index 49bb14b..f389477 100644
--- a/src/wasapi.cpp
+++ b/src/wasapi.cpp
@@ -295,7 +295,6 @@ static void destruct_device(SoundIoDevicePrivate *dev) {
     SoundIoDeviceWasapi *dw = &dev->backend_data.wasapi;
     if (dw->mm_device)
         IMMDevice_Release(dw->mm_device);
-    dw->sample_rates.deinit();
 }
 
 struct RefreshDevices {
@@ -438,7 +437,6 @@ static int add_sample_rate(SoundIoList<SoundIoSampleRateRange> *sample_rates, in
 static int do_sample_rate_test(RefreshDevices *rd, SoundIoDevicePrivate *dev, WAVEFORMATEXTENSIBLE *wave_format,
         int test_sample_rate, AUDCLNT_SHAREMODE share_mode, int *current_min, int *last_success_rate)
 {
-    SoundIoDeviceWasapi *dw = &dev->backend_data.wasapi;
     WAVEFORMATEX *closest_match = nullptr;
     int err;
 
@@ -456,7 +454,7 @@ static int do_sample_rate_test(RefreshDevices *rd, SoundIoDevicePrivate *dev, WA
         *last_success_rate = test_sample_rate;
     } else if (hr == AUDCLNT_E_UNSUPPORTED_FORMAT || hr == S_FALSE || hr == E_INVALIDARG) {
         if (*current_min != -1) {
-            if ((err = add_sample_rate(&dw->sample_rates, current_min, *last_success_rate)))
+            if ((err = add_sample_rate(&dev->sample_rates, current_min, *last_success_rate)))
                 return err;
             *current_min = -1;
         }
@@ -470,12 +468,11 @@ static int do_sample_rate_test(RefreshDevices *rd, SoundIoDevicePrivate *dev, WA
 static int detect_valid_sample_rates(RefreshDevices *rd, WAVEFORMATEXTENSIBLE *wave_format,
         SoundIoDevicePrivate *dev, AUDCLNT_SHAREMODE share_mode)
 {
-    SoundIoDeviceWasapi *dw = &dev->backend_data.wasapi;
     int err;
 
     DWORD orig_sample_rate = wave_format->Format.nSamplesPerSec;
 
-    assert(dw->sample_rates.length == 0);
+    assert(dev->sample_rates.length == 0);
 
     int current_min = -1;
     int last_success_rate = -1;
@@ -492,7 +489,7 @@ static int detect_valid_sample_rates(RefreshDevices *rd, WAVEFORMATEXTENSIBLE *w
     }
 
     if (current_min != -1) {
-        if ((err = add_sample_rate(&dw->sample_rates, &current_min, last_success_rate))) {
+        if ((err = add_sample_rate(&dev->sample_rates, &current_min, last_success_rate))) {
             wave_format->Format.nSamplesPerSec = orig_sample_rate;
             return err;
         }
@@ -500,8 +497,8 @@ static int detect_valid_sample_rates(RefreshDevices *rd, WAVEFORMATEXTENSIBLE *w
 
     SoundIoDevice *device = &dev->pub;
 
-    device->sample_rate_count = dw->sample_rates.length;
-    device->sample_rates = dw->sample_rates.items;
+    device->sample_rate_count = dev->sample_rates.length;
+    device->sample_rates = dev->sample_rates.items;
 
     wave_format->Format.nSamplesPerSec = orig_sample_rate;
     return 0;
diff --git a/src/wasapi.hpp b/src/wasapi.hpp
index 003ed47..910ed19 100644
--- a/src/wasapi.hpp
+++ b/src/wasapi.hpp
@@ -27,7 +27,6 @@
 int soundio_wasapi_init(struct SoundIoPrivate *si);
 
 struct SoundIoDeviceWasapi {
-    SoundIoList<SoundIoSampleRateRange> sample_rates;
     double period_duration;
     IMMDevice *mm_device;
 };