diff --git a/apps/dsp.h b/apps/dsp.h
index 65cd837c1e..8b2a51df51 100644
--- a/apps/dsp.h
+++ b/apps/dsp.h
@@ -27,7 +27,6 @@
 #define NATIVE_FREQUENCY       44100
 #define STEREO_INTERLEAVED     0
 #define STEREO_NONINTERLEAVED  1
-/* Not supported yet. */
 #define STEREO_MONO            2
 
 struct dsp_configuration {
diff --git a/firmware/pcm_playback.c b/firmware/pcm_playback.c
index 20cd1f2dbd..be7f4e4379 100644
--- a/firmware/pcm_playback.c
+++ b/firmware/pcm_playback.c
@@ -47,8 +47,7 @@
 /* Must be a power of 2 */
 #define NUM_PCM_BUFFERS      (PCMBUF_SIZE / CHUNK_SIZE)
 #define NUM_PCM_BUFFERS_MASK (NUM_PCM_BUFFERS - 1)
-//#define PCM_WATERMARK        (CHUNK_SIZE * 6)
-#define PCM_WATERMARK        (PCMBUF_SIZE - CHUNK_SIZE*8)
+#define PCM_WATERMARK        (CHUNK_SIZE * 10)
 #define PCM_CF_WATERMARK     (PCMBUF_SIZE - CHUNK_SIZE*8)
 
 static bool pcm_playing;