diff --git a/dlls/winealsa.drv/dsoutput.c b/dlls/winealsa.drv/dsoutput.c
index 6d0df2118a8..9d6347570e5 100644
--- a/dlls/winealsa.drv/dsoutput.c
+++ b/dlls/winealsa.drv/dsoutput.c
@@ -247,6 +247,7 @@ static int DSDB_CreateMMAP(IDsDriverBufferImpl* pdbi)
             return DSERR_OUTOFMEMORY;
 
         snd_pcm_format_set_silence(format, buf, pdbi->mmap_buflen_frames);
+        pdbi->mmap_pos = 0;
     }
     else
     {