diff --git a/include/hwapi.h b/include/hwapi.h
index 892e9f9..c983fe3 100644
--- a/include/hwapi.h
+++ b/include/hwapi.h
@@ -73,8 +73,10 @@ V4.0  6.9.2023: activating DC-Bootloader in slve-lib (SM)
 //for CAslave:
 //#undef THIS_IS_CA_MASTER
 
-//for CAmaster:	
+//for CAmaster:
+#ifndef THIS_IS_CA_MASTER
 #define THIS_IS_CA_MASTER
+#endif