diff --git a/jetty-deploy/src/main/java/org/eclipse/jetty/deploy/WebAppDeployer.java b/jetty-deploy/src/main/java/org/eclipse/jetty/deploy/WebAppDeployer.java
index 0caabb4f131..540f6ee939f 100644
--- a/jetty-deploy/src/main/java/org/eclipse/jetty/deploy/WebAppDeployer.java
+++ b/jetty-deploy/src/main/java/org/eclipse/jetty/deploy/WebAppDeployer.java
@@ -269,7 +269,7 @@ public class WebAppDeployer extends AbstractLifeCycle
             wah.setParentLoaderPriority(_parentLoaderPriority);
             
             //set up any contextAttributes
-            wah.setAttributes(_contextAttributes);
+            wah.setAttributes(new AttributesMap(_contextAttributes));
             
             // add it
             _contexts.addHandler(wah);