diff --git a/src/engine/platform/zxbeeper.cpp b/src/engine/platform/zxbeeper.cpp
index 7bd992f81..f8762c7f2 100644
--- a/src/engine/platform/zxbeeper.cpp
+++ b/src/engine/platform/zxbeeper.cpp
@@ -90,7 +90,7 @@ void DivPlatformZXBeeper::tick(bool sysTick) {
     if (chan[i].std.pitch.had) {
       if (chan[i].std.pitch.mode) {
         chan[i].pitch2+=chan[i].std.pitch.val;
-        CLAMP_VAR(chan[i].pitch2,-32768,32767);
+        CLAMP_VAR(chan[i].pitch2,-65535,65535);
       } else {
         chan[i].pitch2=chan[i].std.pitch.val;
       }
@@ -99,6 +99,7 @@ void DivPlatformZXBeeper::tick(bool sysTick) {
     if (chan[i].freqChanged || chan[i].keyOn || chan[i].keyOff) {
       if (chan[i].active) {
         chan[i].freq=parent->calcFreq(chan[i].baseFreq,chan[i].pitch,chan[i].fixedArp?chan[i].baseNoteOverride:chan[i].arpOff,chan[i].fixedArp,false,2,chan[i].pitch2,chipClock,CHIP_FREQBASE);
+        if (chan[i].freq<0) chan[i].freq=0;
         if (chan[i].freq>65535) chan[i].freq=65535;
       }
       if (chan[i].keyOn) {