diff --git a/src/engine/platform/pv1000.cpp b/src/engine/platform/pv1000.cpp
index af4cae0c7..903748b6d 100644
--- a/src/engine/platform/pv1000.cpp
+++ b/src/engine/platform/pv1000.cpp
@@ -78,10 +78,10 @@ void DivPlatformPV1000::tick(bool sysTick) {
       if (chan[i].freq>62) chan[i].freq=62;
       if (isMuted[i]) chan[i].keyOn=false;
       if (chan[i].keyOn) {
-        rWrite(i,(isMuted[i] || (chan[i].outVol<=0)) ? 0 : chan[i].freq);
+        rWrite(i,(isMuted[i] || (chan[i].outVol<=0)) ? 0x3f : chan[i].freq);
         chan[i].keyOn=false;
       } else if (chan[i].freqChanged && chan[i].active && !isMuted[i]) {
-        rWrite(i,(isMuted[i] || (chan[i].outVol<=0)) ? 0 : chan[i].freq);
+        rWrite(i,(isMuted[i] || (chan[i].outVol<=0)) ? 0x3f : chan[i].freq);
       }
       if (chan[i].keyOff) {
         rWrite(i,0x3f);
diff --git a/src/engine/platform/sound/d65modified.c b/src/engine/platform/sound/d65modified.c
index edbb21a94..ff5a84da3 100644
--- a/src/engine/platform/sound/d65modified.c
+++ b/src/engine/platform/sound/d65modified.c
@@ -138,12 +138,14 @@ void d65010g031_write(struct d65010g031_t *d65010g031, const unsigned char a, co
 			d65010g031->ctrl = d;
 			break;
 		default:
-			unsigned char per = (unsigned char)(~d) & 0x3f;
+		{
+			const unsigned char per = (unsigned char)(~d) & 0x3f;
 			if ((per == 0) && (d65010g031->square[a].period != 0))
 			{
 				d65010g031->square[a].out ^= 1;
 			}
 			d65010g031->square[a].period = per;
 			break;
+		}
 	}
 }