diff --git a/src/engine/platform/ay.cpp b/src/engine/platform/ay.cpp
index 4a2a4b59..be2ac933 100644
--- a/src/engine/platform/ay.cpp
+++ b/src/engine/platform/ay.cpp
@@ -337,6 +337,7 @@ void DivPlatformAY8910::tick(bool sysTick) {
         chan[i].dac.rate=((double)rate*((sunsoft||clockSel)?8.0:16.0))/(double)(MAX(1,off*chan[i].freq));
         if (dumpWrites) addWrite(0xffff0001+(i<<8),chan[i].dac.rate);
       }
+      if (chan[i].freq<0) chan[i].freq=0;
       if (chan[i].freq>4095) chan[i].freq=4095;
       if (chan[i].keyOn) {
         //rWrite(16+i*5+1,((chan[i].duty&3)<<6)|(63-(ins->gb.soundLen&63)));
diff --git a/src/engine/platform/ay8930.cpp b/src/engine/platform/ay8930.cpp
index 85eca751..4c728fb4 100644
--- a/src/engine/platform/ay8930.cpp
+++ b/src/engine/platform/ay8930.cpp
@@ -336,6 +336,7 @@ void DivPlatformAY8930::tick(bool sysTick) {
         chan[i].dac.rate=((double)chipClock*4.0)/(double)(MAX(1,off*chan[i].freq));
         if (dumpWrites) addWrite(0xffff0001+(i<<8),chan[i].dac.rate);
       }
+      if (chan[i].freq<0) chan[i].freq=0;
       if (chan[i].freq>65535) chan[i].freq=65535;
       if (chan[i].keyOn) {
         if (!chan[i].nextPSGMode.dac) {