diff --git a/FL/glut.H b/FL/glut.H
index ba7a70e68..a447f4fe6 100644
--- a/FL/glut.H
+++ b/FL/glut.H
@@ -189,7 +189,7 @@ inline int glutGetMenu() {return glut_menu;}
 
 inline void glutSetMenu(int m) {glut_menu = m;}
 
-FL_EXPORT void glutAddMenuEntry(char *label, int value);
+FL_EXPORT void glutAddMenuEntry(const char *label, int value);
 
 FL_EXPORT void glutAddSubMenu(char *label, int submenu);
 
diff --git a/src/glut_compatibility.cxx b/src/glut_compatibility.cxx
index 7f3821b77..15fd07f36 100644
--- a/src/glut_compatibility.cxx
+++ b/src/glut_compatibility.cxx
@@ -329,7 +329,7 @@ static Fl_Menu_Item* additem(menu *m) {
   return i;
 }
 
-void glutAddMenuEntry(char *label, int value) {
+void glutAddMenuEntry(const char *label, int value) {
   menu *m = &menus[glut_menu];
   Fl_Menu_Item* i = additem(m);
   i->text = label;