diff --git a/openjpa-kernel/src/main/java/org/apache/openjpa/kernel/MethodStoreQuery.java b/openjpa-kernel/src/main/java/org/apache/openjpa/kernel/MethodStoreQuery.java
index a69be2ece..141ac7850 100644
--- a/openjpa-kernel/src/main/java/org/apache/openjpa/kernel/MethodStoreQuery.java
+++ b/openjpa-kernel/src/main/java/org/apache/openjpa/kernel/MethodStoreQuery.java
@@ -248,6 +248,10 @@ public class MethodStoreQuery
             }
             if (!Modifier.isStatic(meth.getModifiers()))
                 throw new UserException(_loc.get("method-not-static", meth));
+            if (!ResultObjectProvider.class.isAssignableFrom(
+                meth.getReturnType()))
+                throw new UserException(_loc.get("method-return-type-invalid",
+                    meth, meth.getReturnType()));
             _meth = meth;
         }
 
diff --git a/openjpa-kernel/src/main/resources/org/apache/openjpa/kernel/localizer.properties b/openjpa-kernel/src/main/resources/org/apache/openjpa/kernel/localizer.properties
index 89cf8454c..9de8e4926 100644
--- a/openjpa-kernel/src/main/resources/org/apache/openjpa/kernel/localizer.properties
+++ b/openjpa-kernel/src/main/resources/org/apache/openjpa/kernel/localizer.properties
@@ -300,6 +300,9 @@ bad-method-class: You set the method name of this openjpa.MethodQL query to \
 	qualify the class name or to import its package into this query if the \
 	class is not in the query candidate class'' package. 
 method-not-static: Method "{0}" named in the MethodQL query must be static.
+method-return-type-invalid: Method "{0}" named in the MethodQL query must \
+    have a return type that is assignable from ResultObjectProvider. Return \
+    type is: {1}.
 no-method: You must set the query filter to the name of the method to execute \
 	for this MethodQL query instance.
 method-error: There was an error invoking method "{0}" with arguments "{1}".