diff --git a/mozilla/xpcom/base/nsAllocator.h b/mozilla/xpcom/base/nsAllocator.h
index b25659e1845..8d0baad2b7c 100644
--- a/mozilla/xpcom/base/nsAllocator.h
+++ b/mozilla/xpcom/base/nsAllocator.h
@@ -83,7 +83,7 @@ public:
     NS_IMETHOD LockFactory(PRBool aLock);
 
     nsAllocatorFactory(void);
-    ~nsAllocatorFactory(void);
+    virtual ~nsAllocatorFactory(void);
 
     NS_DECL_ISUPPORTS
 };
diff --git a/mozilla/xpcom/src/nsAllocator.h b/mozilla/xpcom/src/nsAllocator.h
index b25659e1845..8d0baad2b7c 100644
--- a/mozilla/xpcom/src/nsAllocator.h
+++ b/mozilla/xpcom/src/nsAllocator.h
@@ -83,7 +83,7 @@ public:
     NS_IMETHOD LockFactory(PRBool aLock);
 
     nsAllocatorFactory(void);
-    ~nsAllocatorFactory(void);
+    virtual ~nsAllocatorFactory(void);
 
     NS_DECL_ISUPPORTS
 };