diff --git a/src/hwapi.cpp b/src/hwapi.cpp
index 8ea004e..e97d6ce 100644
--- a/src/hwapi.cpp
+++ b/src/hwapi.cpp
@@ -49,9 +49,19 @@ hwapi::hwapi(QWidget *parent) : QObject(parent)
 //    {
 
 #ifdef THIS_IS_CA_MASTER
+
+#ifdef THIS_IS_CA_SLAVE
+#error "SLAVE LIB COMPILED INTO MASTER"
+#endif
+
         myDatif = new T_datif();    // für die  CAslave-Lib auskommentieren!
+
 #else
-    qCritical()<<"hwapi: error CAslave cannot include T_datif";
+
+#ifdef THIS_IS_CA_MASTER
+#error "MASTER LIB COMPILED INTO MASTER"
+#endif	
+
 #endif
 
 //    }