diff --git a/src/gui.c b/src/gui.c
index 4408545..e708a27 100644
--- a/src/gui.c
+++ b/src/gui.c
@@ -32,6 +32,7 @@
 static void gui_update_horiz_scrollbar(int);
 static void gui_set_fg_color(char_u *name);
 static void gui_set_bg_color(char_u *name);
+static void init_gui_options(void);
 static win_T *xy2win(int x, int y, mouse_find_T popup);
 
 #ifdef GUI_MAY_FORK
@@ -1395,7 +1396,7 @@
 }
 
 #if defined(FEAT_MENU) || defined(PROTO)
-    void
+    static void
 gui_position_menu(void)
 {
 # if !defined(FEAT_GUI_GTK) && !defined(FEAT_GUI_MOTIF)
@@ -4815,7 +4816,7 @@
 /*
  * Option initializations that can only be done after opening the GUI window.
  */
-    void
+    static void
 init_gui_options(void)
 {
     // Set the 'background' option according to the lightness of the