diff --git a/DCC.cpp b/DCC.cpp
index e60cf25..a5eafec 100644
--- a/DCC.cpp
+++ b/DCC.cpp
@@ -229,15 +229,9 @@ bool DCC::setFn( int cab, int16_t functionNumber, bool on) {
 
 // Flip function state (used from withrottle protocol)
 void DCC::changeFn( int cab, int16_t functionNumber) {
-  if (cab<=0 || functionNumber>31) return;
-  int reg = lookupSpeedTable(cab);
-  if (reg<0) return;
-  unsigned long funcmask = (1UL<<functionNumber);
-  speedTable[reg].functions ^= funcmask;
-  if (functionNumber <= 28) {
-    updateGroupflags(speedTable[reg].groupFlags, functionNumber);
-  }
-  CommandDistributor::broadcastLoco(reg);
+  auto currentValue=getFn(cab,functionNumber);
+  if (currentValue<0) return;  // function not valid for change  
+  setFn(cab,functionNumber, currentValue?false:true);
 }
 
 // Report function state (used from withrottle protocol)
diff --git a/version.h b/version.h
index a279772..5ec1022 100644
--- a/version.h
+++ b/version.h
@@ -3,7 +3,8 @@
 
 #include "StringFormatter.h"
 
-#define VERSION "5.4.1"
+#define VERSION "5.4.2"
+// 5.4.2  - Bugfix function flip >28
 // 5.4.1  - ESP32 bugfix packet buffer race
 // 5.4.0  - New version on master
 // 5.2.96 - EXRAIL additions XFWD() and XREV()