diff --git a/proposal/myrmidon/src/java/org/apache/antlib/extensions/JarLibManifestTask.java b/proposal/myrmidon/src/java/org/apache/antlib/extensions/JarLibManifestTask.java
index da9311369..728e24ae1 100644
--- a/proposal/myrmidon/src/java/org/apache/antlib/extensions/JarLibManifestTask.java
+++ b/proposal/myrmidon/src/java/org/apache/antlib/extensions/JarLibManifestTask.java
@@ -184,7 +184,10 @@ public final class JarLibManifestTask
 
         appendExtraAttributes( attributes );
 
-        Extension.addExtension( m_extension, attributes );
+        if( null != m_extension )
+        {
+            Extension.addExtension( m_extension, attributes );
+        }
 
         //Add all the dependency data to manifest for dependencies
         final ArrayList depends = toExtensions( m_dependencies );