diff --git a/src/engine/platform/opl.cpp b/src/engine/platform/opl.cpp
index 36dd2c66b..a32777c33 100644
--- a/src/engine/platform/opl.cpp
+++ b/src/engine/platform/opl.cpp
@@ -293,7 +293,7 @@ void DivPlatformOPL::acquire_nuked(short* bufL, short* bufR, size_t start, size_
       if (!isMuted[adpcmChan]) {
         os[0]-=aOut.data[0]>>3;
         os[1]-=aOut.data[0]>>3;
-        oscBuf[adpcmChan]->data[oscBuf[adpcmChan]->needle++]+=aOut.data[0];
+        oscBuf[adpcmChan]->data[oscBuf[adpcmChan]->needle++]=aOut.data[0];
       } else {
         oscBuf[adpcmChan]->data[oscBuf[adpcmChan]->needle++]=0;
       }