--- a/jdk/src/share/classes/java/util/IdentityHashMap.java	Fri Sep 13 12:20:53 2013 +0100
+++ b/jdk/src/share/classes/java/util/IdentityHashMap.java	Fri Sep 13 11:18:44 2013 -0700
@@ -997,6 +997,7 @@
          * behavior when c is a smaller "normal" (non-identity-based) Set.
          */
         public boolean removeAll(Collection<?> c) {
+            Objects.requireNonNull(c);
             boolean modified = false;
             for (Iterator<K> i = iterator(); i.hasNext(); ) {
                 if (c.contains(i.next())) {
@@ -1212,6 +1213,7 @@
          * behavior when c is a smaller "normal" (non-identity-based) Set.
          */
         public boolean removeAll(Collection<?> c) {
+            Objects.requireNonNull(c);
             boolean modified = false;
             for (Iterator<Map.Entry<K,V>> i = iterator(); i.hasNext(); ) {
                 if (c.contains(i.next())) {