diff --git a/NmraDcc.cpp b/NmraDcc.cpp
index 5fef252..1a86292 100644
--- a/NmraDcc.cpp
+++ b/NmraDcc.cpp
@@ -927,10 +927,18 @@ void processServiceModeOperation( DCC_MSG * pDccMsg )
 #endif
 void resetServiceModeTimer(uint8_t inServiceMode)
 {
+  if (notifyServiceMode && inServiceMode != DccProcState.inServiceMode)
+  {
+    notifyServiceMode(inServiceMode);
+  }
   // Set the Service Mode
   DccProcState.inServiceMode = inServiceMode ;
   
   DccProcState.LastServiceModeMillis = inServiceMode ? millis() : 0 ;
+  if (notifyServiceMode && inServiceMode != DccProcState.inServiceMode)
+  {
+    notifyServiceMode(inServiceMode);
+  }
 }
 
 void clearDccProcState(uint8_t inServiceMode)
@@ -1428,4 +1436,4 @@ uint8_t NmraDcc::process()
   }
 
   return 0 ;  
-};
\ No newline at end of file
+};
diff --git a/NmraDcc.h b/NmraDcc.h
index 3f5d17b..b1ecf1e 100644
--- a/NmraDcc.h
+++ b/NmraDcc.h
@@ -669,6 +669,7 @@ extern void    notifyCVResetFactoryDefault(void) __attribute__ ((weak));
  *    None
  */
 extern void    notifyCVAck(void) __attribute__ ((weak));
+extern void    notifyServiceMode(bool) __attribute__ ((weak));
 
 #if defined (__cplusplus)
 }