--- a/graal/com.oracle.truffle.dsl.processor/src/com/oracle/truffle/dsl/processor/model/ParameterSpec.java	Tue Apr 14 15:12:48 2015 +0200
+++ b/graal/com.oracle.truffle.dsl.processor/src/com/oracle/truffle/dsl/processor/model/ParameterSpec.java	Tue Apr 14 15:12:48 2015 +0200
@@ -27,6 +27,7 @@
 import javax.lang.model.element.*;
 import javax.lang.model.type.*;
 
+import com.oracle.truffle.dsl.processor.*;
 import com.oracle.truffle.dsl.processor.java.*;
 import com.oracle.truffle.dsl.processor.model.MethodSpec.TypeDef;
 
@@ -127,7 +128,7 @@
             }
             if (allowSubclasses) {
                 for (TypeMirror type : allowedTypes) {
-                    if (ElementUtils.isAssignable(variable.asType(), type)) {
+                    if (ElementUtils.isSubtypeBoxed(ProcessorContext.getInstance(), variable.asType(), type)) {
                         return true;
                     }
                 }