diff --git a/jetty-webapp/src/main/java/org/eclipse/jetty/webapp/WebAppContext.java b/jetty-webapp/src/main/java/org/eclipse/jetty/webapp/WebAppContext.java
index 4e50541939e..bc4a3de8802 100644
--- a/jetty-webapp/src/main/java/org/eclipse/jetty/webapp/WebAppContext.java
+++ b/jetty-webapp/src/main/java/org/eclipse/jetty/webapp/WebAppContext.java
@@ -327,6 +327,9 @@ public class WebAppContext extends ServletContextHandler implements WebAppClassL
     @Override
     public Resource getResource(String uriInContext) throws MalformedURLException
     {
+        if (uriInContext==null || !uriInContext.startsWith(URIUtil.SLASH))
+            throw new MalformedURLException(uriInContext);
+
         IOException ioe= null;
         Resource resource= null;
         int loop=0;