diff --git a/src/engine/platform/supervision.cpp b/src/engine/platform/supervision.cpp
index c291115e3..112fcb572 100644
--- a/src/engine/platform/supervision.cpp
+++ b/src/engine/platform/supervision.cpp
@@ -53,7 +53,7 @@ const char* regCheatSheetSupervision[]={
 };
 
 unsigned char noiseReg[3];
-unsigned char kon[3];
+unsigned char kon[4];
 unsigned char initWrite[4];
 
 const char** DivPlatformSupervision::getRegisterSheet() {
@@ -436,7 +436,7 @@ void DivPlatformSupervision::reset() {
   memset(tempL,0,32*sizeof(int));
   memset(tempR,0,32*sizeof(int));
   memset(noiseReg,0,3*sizeof(unsigned char));
-  memset(kon,0,3*sizeof(unsigned char));
+  memset(kon,0,4*sizeof(unsigned char));
   memset(initWrite,1,sizeof(unsigned char));
   sampleOffset=0;
 }
diff --git a/src/engine/platform/supervision.h b/src/engine/platform/supervision.h
index f5025bc47..c9fa81bda 100644
--- a/src/engine/platform/supervision.h
+++ b/src/engine/platform/supervision.h
@@ -30,7 +30,7 @@ class DivPlatformSupervision: public DivDispatch {
     int sample, hasOffset; // again, for channel 3 ONLY
     bool setPos;
     Channel():
-      SharedChannel<signed char>(31),
+      SharedChannel<signed char>(63),
       duty(0),
       len(0x1f),
       pan(3),