diff --git a/src/bin/win.h b/src/bin/win.h
index e08a9b8d..c629f2d3 100644
--- a/src/bin/win.h
+++ b/src/bin/win.h
@@ -90,6 +90,6 @@ void
 term_apply_shine(Term *term, int shine);
 void background_set_shine(Config *config, Evas_Object *bg);
 
-void main_trans_update();
+void main_trans_update(void);
 
 #endif