diff --git a/xpcom/ds/nsIEnumerator.h b/xpcom/ds/nsIEnumerator.h
index 54d3b142e37..16a9ba53ac6 100644
--- a/xpcom/ds/nsIEnumerator.h
+++ b/xpcom/ds/nsIEnumerator.h
@@ -56,7 +56,7 @@ public:
    *  and it is the end of the list following a call to next
    *  @param aItem return value
    */
-  virtual nsresult IsDone(PRBool *aDone)=0;
+  virtual nsresult IsDone()=0;
 
 };
 
diff --git a/xpcom/public/nsIEnumerator.h b/xpcom/public/nsIEnumerator.h
index 54d3b142e37..16a9ba53ac6 100644
--- a/xpcom/public/nsIEnumerator.h
+++ b/xpcom/public/nsIEnumerator.h
@@ -56,7 +56,7 @@ public:
    *  and it is the end of the list following a call to next
    *  @param aItem return value
    */
-  virtual nsresult IsDone(PRBool *aDone)=0;
+  virtual nsresult IsDone()=0;
 
 };