diff --git a/src/engine/platform/zxbeeperqt.cpp b/src/engine/platform/zxbeeperqt.cpp
index 0ac046db..fbd47757 100644
--- a/src/engine/platform/zxbeeperqt.cpp
+++ b/src/engine/platform/zxbeeperqt.cpp
@@ -138,7 +138,7 @@ void DivPlatformZXBeeperQT::tick(bool sysTick) {
         off=(s->centerRate>=1)?(CHIP_DIVIDER*(double)s->centerRate/8363.0):CHIP_DIVIDER;
       }
       chan[4].freq=parent->calcFreq(chan[4].baseFreq,chan[4].pitch,chan[4].fixedArp?chan[4].baseNoteOverride:chan[4].arpOff,chan[4].fixedArp,true,2,chan[4].pitch2,chipClock,off);
-      if (chan[4].freq>259) chan[4].freq=259;
+      if (chan[4].freq>258) chan[4].freq=258;
       if (chan[4].freq<3) chan[4].freq=3;
       chan[4].freq*=13;
     }