--- a/js/xpconnect/src/XPCWrappedNativeInfo.cpp
+++ b/js/xpconnect/src/XPCWrappedNativeInfo.cpp
@@ -437,24 +437,22 @@ XPCNativeSetKey::Hash() const
     PLDHashNumber h = 0;
 
     if (!mBaseSet) {
         MOZ_ASSERT(mAddition, "bad key");
         h ^= HashPointer(mAddition);
     } else {
         XPCNativeInterface** current = mBaseSet->GetInterfaceArray();
         uint16_t count = mBaseSet->GetInterfaceCount();
+        for (uint16_t i = 0; i < count; i++) {
+            h ^= HashPointer(*(current++));
+        }
+
         if (mAddition) {
-            for (uint16_t i = 0; i < count; i++) {
-                h ^= HashPointer(*(current++));
-            }
             h ^= HashPointer(mAddition);
-        } else {
-            for (uint16_t i = 0; i < count; i++)
-                h ^= HashPointer(*(current++));
         }
     }
 
     return h;
 }
 
 /***************************************************************************/
 // XPCNativeSet