diff --git a/src/osx/uiaction_osx.cpp b/src/osx/uiaction_osx.cpp
index 2f8088f8c2..602b7b023d 100644
--- a/src/osx/uiaction_osx.cpp
+++ b/src/osx/uiaction_osx.cpp
@@ -228,7 +228,8 @@ bool wxUIActionSimulator::MouseUp(int button)
     return true;
 }
 
-bool wxUIActionSimulator::DoKey(int keycode, int modifiers, bool isDown)
+bool
+wxUIActionSimulator::DoKey(int keycode, int WXUNUSED(modifiers), bool isDown)
 {
     CGKeyCode cgcode = wxCharCodeWXToOSX((wxKeyCode)keycode);
 
@@ -241,7 +242,5 @@ bool wxUIActionSimulator::DoKey(int keycode, int modifiers, bool isDown)
     return true;
 }
 
-}
-
 #endif // wxUSE_UIACTIONSIMULATOR