diff --git a/openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/kernel/exps/GetMapValue.java b/openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/kernel/exps/GetMapValue.java
index c41f11396..fac53599f 100644
--- a/openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/kernel/exps/GetMapValue.java
+++ b/openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/kernel/exps/GetMapValue.java
@@ -176,7 +176,7 @@ class GetMapValue
         if (clss != null && clss.length > 1)
             throw RelationStrategies.unjoinable(field);
 
-        ClassMapping cls = (clss.length == 0) ? null : clss[0];
+        ClassMapping cls = (clss == null || clss.length == 0) ? null : clss[0];
         ForeignKey fk = strat.getJoinForeignKey(cls);
 
         // manually create a subselect for the Map's value