diff --git a/src/gui.c b/src/gui.c
index a7216fc..3df9921 100644
--- a/src/gui.c
+++ b/src/gui.c
@@ -803,8 +803,8 @@
 	if (!p_beval)
 	    gui_mch_disable_beval_area(balloonEval);
 #endif
-	// In case the terminal was used before ":gui".
-	seenModifyOtherKeys = FALSE;
+	// In the GUI modifiers are prepended to keys.
+	seenModifyOtherKeys = TRUE;
 
 #if defined(FEAT_XIM) && defined(FEAT_GUI_GTK)
 	if (!im_xim_isvalid_imactivate())