use given type system
diff --git a/plugins/org.eclipse.xpand/src/org/eclipse/xpand2/XpandExecutionContextImpl.java b/plugins/org.eclipse.xpand/src/org/eclipse/xpand2/XpandExecutionContextImpl.java
index 16e4262..a01e125 100644
--- a/plugins/org.eclipse.xpand/src/org/eclipse/xpand2/XpandExecutionContextImpl.java
+++ b/plugins/org.eclipse.xpand/src/org/eclipse/xpand2/XpandExecutionContextImpl.java
@@ -119,7 +119,7 @@
 		    ExceptionHandler exceptionHandler,
 		    NullEvaluationHandler nullEvaluationHandler) {
     	super(ts, globalVars);
-        registerMetaModel(new XpandTypesMetaModel(this));
+        registerMetaModel(new XpandTypesMetaModel(ts));
         registerParser(resourceManager);
         this.output = output;
         this.protectedRegionResolver = prs;
@@ -158,7 +158,7 @@
         	callback,
         	extensionsForNameAndTypesCache,
         	extensionsReturnTypeCache);
-        registerMetaModel(new XpandTypesMetaModel(this));
+        registerMetaModel(new XpandTypesMetaModel(typeSystem));
         registerParser(resourceManager);
         this.output = output;
         this.protectedRegionResolver = protectedRegionResolver;