| Index: include/AdblockPlus/FilterEngine.h | 
| diff --git a/include/AdblockPlus/FilterEngine.h b/include/AdblockPlus/FilterEngine.h | 
| index 6bb15739c08c1abccea6adb513aadaf9c1d50dd1..c60a8de920165187bb7baadb72fa0d0ba2a4cca5 100644 | 
| --- a/include/AdblockPlus/FilterEngine.h | 
| +++ b/include/AdblockPlus/FilterEngine.h | 
| @@ -468,7 +468,7 @@ namespace AdblockPlus | 
| *        available or not - to react to updates being available, use | 
| *        `FilterEngine::SetUpdateAvailableCallback()`. | 
| */ | 
| -    void ForceUpdateCheck(UpdateCheckDoneCallback callback); | 
| +    void ForceUpdateCheck(const UpdateCheckDoneCallback& callback = UpdateCheckDoneCallback()); | 
|  | 
| /** | 
| * Sets the callback invoked when the filters change. | 
|  |