--- a/accessible/ipc/ProxyAccessible.h
+++ b/accessible/ipc/ProxyAccessible.h
@@ -62,18 +62,17 @@ public:
 
   /*
    * Return the ID of the accessible being proxied.
    */
   uint64_t ID() const { return mID; }
 
 protected:
   ProxyAccessible() :
-    mParent(nullptr), mDoc(nullptr), mWrapper(0), mID(0)
-  { MOZ_COUNT_CTOR(ProxyAccessible); }
+    mParent(nullptr), mDoc(nullptr) { MOZ_COUNT_CTOR(ProxyAccessible); }
 
 protected:
   ProxyAccessible* mParent;
 
 private:
   nsTArray<ProxyAccessible*> mChildren;
   DocAccessibleParent* mDoc;
   uintptr_t mWrapper;