diff --git a/UI/platform.hpp b/UI/platform.hpp
index 99a90def8..f1ab78191 100644
--- a/UI/platform.hpp
+++ b/UI/platform.hpp
@@ -65,4 +65,5 @@ RunOnceMutex GetRunOnceMutex(bool &already_running);
 #ifdef __APPLE__
 void EnableOSXVSync(bool enable);
 void EnableOSXDockIcon(bool enable);
+void InstallNSApplicationSubclass();
 #endif