diff --git a/core/src/main/java/hudson/Functions.java b/core/src/main/java/hudson/Functions.java
index 9e13aeebcbbcb64d364152abe31476fe2f33cbe6..e3ef07269cb9aa519b01f5bea659045a9d4376e1 100644
--- a/core/src/main/java/hudson/Functions.java
+++ b/core/src/main/java/hudson/Functions.java
@@ -866,6 +866,7 @@ public class Functions {
      */
     public static String getActionUrl(String itUrl,Action action) {
         String urlName = action.getUrlName();
+        if(urlName==null)   return null;    // to avoid NPE and fail to render the whole page
 
         if(SCHEME.matcher(urlName).matches())
             return urlName; // absolute URL
diff --git a/core/src/main/java/hudson/model/Action.java b/core/src/main/java/hudson/model/Action.java
index c77bd1410fdcedbdf1a14af372918cdf065d60e2..89b2065076a11371cec8f02cae903fe5b879caa4 100644
--- a/core/src/main/java/hudson/model/Action.java
+++ b/core/src/main/java/hudson/model/Action.java
@@ -71,7 +71,8 @@ public interface Action extends ModelObject {
      * which is useful for directly connecting to external systems.
      *
      * @return
-     *      null if this action object doesn't need to be bound to web.
+     *      null if this action object doesn't need to be bound to web
+     *      (when you do that, be sure to also return null from {@link #getIconFileName()}.
      */
     String getUrlName();
 }