diff --git a/src/minidexed.cpp b/src/minidexed.cpp
index f1d0079..1236923 100644
--- a/src/minidexed.cpp
+++ b/src/minidexed.cpp
@@ -2197,4 +2197,5 @@ void CMiniDexed::setOperatorMute(uint8_t operatorIndex, unsigned nTG) {
     LOGDBG("Operator %u mute toggled for TG %u. New mask: 0x%02X", operatorIndex, nTG, m_uchOPMask[nTG]);
 
     // Apply the updated operator mask to the tone generator
+    m_pTG[nTG]->setOPAll(m_uchOPMask[nTG]);
 }