diff --git a/src/org/meta_environment/rascal/interpreter/matching/EnumeratorResult.java b/src/org/meta_environment/rascal/interpreter/matching/EnumeratorResult.java
index 4e6b41faa25..05aa68631f4 100644
--- a/src/org/meta_environment/rascal/interpreter/matching/EnumeratorResult.java
+++ b/src/org/meta_environment/rascal/interpreter/matching/EnumeratorResult.java
@@ -91,7 +91,7 @@ private void makeIterator(Type subjectType, IValue subjectValue){
 		// Map
 		} else if(subjectType.isMapType()){
 			checkNoStrategy(subjectType);
-			if(!subjectType.getElementType().isVoidType())
+			if(!subjectType.getKeyType().isVoidType())
 				checkMayOccur(patType, subjectType.getKeyType());
 			iterator = ((IMap) subjectValue).iterator();