diff --git a/src/emu/sound/ym2413.c b/src/emu/sound/ym2413.c
index 757103bc3b6..55ccbf11d94 100644
--- a/src/emu/sound/ym2413.c
+++ b/src/emu/sound/ym2413.c
@@ -1751,7 +1751,7 @@ static void OPLLWriteReg(YM2413 *chip, int r, int v)
 			}
 			else
 			{
-				if ((chip->rhythm&0x20)==1)
+				if (chip->rhythm&0x20)
 				/*rhythm on to off*/
 				{
 					logerror("YM2413: Rhythm mode disable\n");