diff --git a/example/sio_sine.c b/example/sio_sine.c
index cca9b19..c53843e 100644
--- a/example/sio_sine.c
+++ b/example/sio_sine.c
@@ -62,7 +62,7 @@ static void write_callback(struct SoundIoOutStream *outstream, int frame_count_m
     for (;;) {
         int frame_count = frames_left;
         if ((err = soundio_outstream_begin_write(outstream, &areas, &frame_count))) {
-            fprintf(stderr, "%s\n", soundio_strerror(err));
+            fprintf(stderr, "unrecoverable stream error: %s\n", soundio_strerror(err));
             exit(1);
         }
 
@@ -85,7 +85,7 @@ static void write_callback(struct SoundIoOutStream *outstream, int frame_count_m
         if ((err = soundio_outstream_end_write(outstream))) {
             if (err == SoundIoErrorUnderflow)
                 return;
-            fprintf(stderr, "%s\n", soundio_strerror(err));
+            fprintf(stderr, "unrecoverable stream error: %s\n", soundio_strerror(err));
             exit(1);
         }
 
diff --git a/src/alsa.cpp b/src/alsa.cpp
index 56a3013..e94efe0 100644
--- a/src/alsa.cpp
+++ b/src/alsa.cpp
@@ -1091,7 +1091,8 @@ void outstream_thread_run(void *arg) {
                     continue;
                 }
 
-                outstream->write_callback(outstream, 0, avail);
+                if (avail > 0)
+                    outstream->write_callback(outstream, 0, avail);
                 continue;
             }
             case SND_PCM_STATE_XRUN: