diff --git a/soundio/soundio.h b/soundio/soundio.h
index c5a285d..bf5ebef 100644
--- a/soundio/soundio.h
+++ b/soundio/soundio.h
@@ -940,6 +940,8 @@ SOUNDIO_EXPORT int soundio_outstream_open(struct SoundIoOutStream *outstream);
 
 /// After you call this function, SoundIoOutStream::write_callback will be called.
 ///
+/// This function might directly call SoundIoOutStream::write_callback.
+///
 /// Possible errors:
 /// * #SoundIoErrorStreaming
 /// * #SoundIoErrorNoMem