--- a/JavaPackage.st	Wed Apr 01 10:20:10 2015 +0100
+++ b/JavaPackage.st	Fri Apr 03 16:52:38 2015 +0100
@@ -100,7 +100,7 @@
                     thisNamespace isBehavior ifFalse:[
                          self error:'name conflict: java package ' , aName , ' vs. global with the same name'.
                     ].
-                    (thisNamespace ~~ JAVA and:[thisNamespace isJavaPackage not]) ifTrue:[
+                    (thisNamespace ~~ JAVA and:[thisNamespace isJavaPackage not and:[(thisNamespace name startsWith: #'JAVA_') not]]) ifTrue:[
                         self error:'name conflict: non-java package ' , aName , 'aleady exists'.
                     ].
                 ]