diff --git a/openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/ant/MappingToolTask.java b/openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/ant/MappingToolTask.java
index 6706229a5..196033656 100644
--- a/openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/ant/MappingToolTask.java
+++ b/openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/ant/MappingToolTask.java
@@ -176,7 +176,10 @@ public class MappingToolTask
         if (MappingTool.ACTION_IMPORT.equals(flags.action))
             assertFiles(files);
 
-        ClassLoader loader = getClassLoader();
+        ClassLoader loader =
+            (ClassLoader) AccessController.doPrivileged(J2DoPrivHelper
+                    .newTemporaryClassLoaderAction(getClassLoader()));
+        
         if (flags.meta && MappingTool.ACTION_ADD.equals(flags.action))
             flags.metaDataFile = Files.getFile(file, loader);
         else
@@ -190,7 +193,7 @@ public class MappingToolTask
             J2DoPrivHelper.getClassLoaderAction(MappingTool.class)));
         JDBCConfiguration conf = (JDBCConfiguration) getConfiguration();
         conf.setClassResolver(resolver);
-
+        
         if (!MappingTool.run(conf, files, flags, loader))
             throw new BuildException(_loc.get("bad-conf", "MappingToolTask")
                 .getMessage());