diff --git a/src/org/rascalmpl/core/library/B.rsc b/src/org/rascalmpl/core/library/B.rsc
index 9caa6260..89162c1b 100644
--- a/src/org/rascalmpl/core/library/B.rsc
+++ b/src/org/rascalmpl/core/library/B.rsc
@@ -1,5 +1,18 @@
 module B
 
-extend A;
 
-syntax B = A+;
\ No newline at end of file
+import ParseTree;
+
+//syntax B = 'b'; 
+//
+//void X(B t) { 
+//    if (t.src != |unkown:///|) { // gaat goed
+//        throw "";
+//    }
+//}
+
+void X(Tree t2) {
+    if (t2.src != |unkown:///|) { // error
+        throw "";
+    }
+}
\ No newline at end of file
diff --git a/src/org/rascalmpl/core/library/lang/rascalcore/check/RascalConfig.rsc b/src/org/rascalmpl/core/library/lang/rascalcore/check/RascalConfig.rsc
index d845c967..da175d24 100644
--- a/src/org/rascalmpl/core/library/lang/rascalcore/check/RascalConfig.rsc
+++ b/src/org/rascalmpl/core/library/lang/rascalcore/check/RascalConfig.rsc
@@ -191,13 +191,22 @@ AType rascalGetTypeInTypeFromDefine(Define containerDef, str selectorName, set[I
     //println("rascalGetTypeInTypeFromDefine: <containerDef>, <selectorName>");
     //println("commonKeywordFields: <containerDef.defInfo.commonKeywordFields>");
     containerType = s.getType(containerDef.defined);
-    if(fieldId() in idRolesSel && selectorName == "top" && isStartNonTerminalType(containerType)){
+    if(  fieldId() in idRolesSel 
+       && selectorName == "top" 
+       && isStartNonTerminalType(containerType)
+       ){
         return getStartNonTerminalType(containerType);
     }
-    if(fieldId() in idRolesSel && selectorName == "top" && isTreeType(containerType)){
+    if(   fieldId() in idRolesSel 
+       && selectorName == "top" 
+       && isTreeType(containerType)
+       ){
         return containerType;
     }
-    if(keywordFieldId() in idRolesSel && selectorName == "src" &&  isNonTerminalAType(containerType)){
+    if(   keywordFieldId() in idRolesSel 
+       && selectorName == "src" 
+       && (isTreeType(containerType) || isNonTerminalAType(containerType))
+       ){
         return aloc();
     }