one more small fix in unit test java template
diff --git a/java_gen/templates/unit_test.java b/java_gen/templates/unit_test.java
index 7fb52bb..5a525e4 100644
--- a/java_gen/templates/unit_test.java
+++ b/java_gen/templates/unit_test.java
@@ -46,7 +46,7 @@
     //:: var_name = msg.interface.variable_name
     //:: builder_method = factory.method_name(msg.interface)
     //:: factory_impl = java_model.model.factory_of(test.interface).of_version(test.java_class.version).name
-    ${factory.name if factory.name is not None else OFFactory} factory;
+    ${factory.name if factory.name is not None else "OFFactory"} factory;
 
     final static byte[] ${msg.constant_name}_SERIALIZED =
         new byte[] { ${", ".join("%s0x%x" % (("" if ord(c)<128 else "(byte) "),  ord(c)) for c in test_data["binary"] ) } };