diff --git a/dlls/dsound/dsound_main.c b/dlls/dsound/dsound_main.c
index 532a682..a8def0f 100644
--- a/dlls/dsound/dsound_main.c
+++ b/dlls/dsound/dsound_main.c
@@ -186,7 +186,7 @@
 
 /* #define USE_DSOUND3D 1 */
 
-#define DSOUND_FRAGLEN (primarybuf->wfx.nAvgBytesPerSec >> 4)
+#define DSOUND_FRAGLEN ((primarybuf->wfx.nAvgBytesPerSec >> 4) & ~3)
 #define DSOUND_FREQSHIFT (14)
 
 static int audiofd = -1;