diff --git a/src/engine/platform/gb.cpp b/src/engine/platform/gb.cpp
index 942032e32..ea6ad7719 100644
--- a/src/engine/platform/gb.cpp
+++ b/src/engine/platform/gb.cpp
@@ -97,8 +97,12 @@ void DivPlatformGB::updateWave() {
     if (wt->max<1 || wt->len<1) {
       rWrite(0x30+i,0);
     } else {
-      unsigned char nibble1=15-((wt->data[(i*2)*wt->len/32]*15)/wt->max);
-      unsigned char nibble2=15-((wt->data[(1+i*2)*wt->len/32]*15)/wt->max);
+      int nibble1=15-((wt->data[(i*2)*wt->len/32]*15)/wt->max);
+      int nibble2=15-((wt->data[(1+i*2)*wt->len/32]*15)/wt->max);
+      if (nibble1<0) nibble1=0;
+      if (nibble1>15) nibble1=15;
+      if (nibble2<0) nibble2=0;
+      if (nibble2>15) nibble2=15;
       rWrite(0x30+i,(nibble1<<4)|nibble2);
     }
   }
diff --git a/src/engine/platform/pce.cpp b/src/engine/platform/pce.cpp
index 296eafc41..1af1741c5 100644
--- a/src/engine/platform/pce.cpp
+++ b/src/engine/platform/pce.cpp
@@ -138,7 +138,10 @@ void DivPlatformPCE::updateWave(int ch) {
     if (wt->max<1 || wt->len<1) {
       chWrite(ch,0x06,0);
     } else {
-      chWrite(ch,0x06,wt->data[i*wt->len/32]*31/wt->max);
+      int data=wt->data[i*wt->len/32]*31/wt->max;
+      if (data<0) data=0;
+      if (data>31) data=31;
+      chWrite(ch,0x06,data);
     }
   }
   if (chan[ch].active) {
diff --git a/src/engine/platform/swan.cpp b/src/engine/platform/swan.cpp
index 219871804..de6236478 100644
--- a/src/engine/platform/swan.cpp
+++ b/src/engine/platform/swan.cpp
@@ -119,8 +119,12 @@ void DivPlatformSwan::updateWave(int ch) {
     }
   } else {
     for (int i=0; i<16; i++) {
-      unsigned char nibble1=(wt->data[(i*2)*wt->len/32]*15)/wt->max;
-      unsigned char nibble2=(wt->data[(1+i*2)*wt->len/32]*15)/wt->max;
+      int nibble1=(wt->data[(i*2)*wt->len/32]*15)/wt->max;
+      int nibble2=(wt->data[(1+i*2)*wt->len/32]*15)/wt->max;
+      if (nibble1<0) nibble1=0;
+      if (nibble1>15) nibble1=15;
+      if (nibble2<0) nibble2=0;
+      if (nibble2>15) nibble2=15;
       rWrite(addr+i,nibble1|(nibble2<<4));
     }
   }
diff --git a/src/engine/platform/x1_010.cpp b/src/engine/platform/x1_010.cpp
index 42853855a..1782deb9d 100644
--- a/src/engine/platform/x1_010.cpp
+++ b/src/engine/platform/x1_010.cpp
@@ -282,7 +282,10 @@ void DivPlatformX1_010::updateWave(int ch) {
     if (wt->max<1 || wt->len<1) {
       waveWrite(ch,i,0);
     } else {
-      waveWrite(ch,i,wt->data[i*wt->len/128]*255/wt->max);
+      int data=wt->data[i*wt->len/128]*255/wt->max;
+      if (data<0) data=0;
+      if (data>255) data=255;
+      waveWrite(ch,i,data);
     }
   }
   if (!chan[ch].pcm) {