diff --git a/cmd.c b/cmd.c
index ecca167..f77897e 100644
--- a/cmd.c
+++ b/cmd.c
@@ -389,7 +389,7 @@ cvtnum(
 	if (sp[1] != '\0')
 		return -1LL;
 
-	c = tolower(*sp);
+	c = qemu_tolower(*sp);
 	switch (c) {
 	default:
 		return i;
diff --git a/ui/keymaps.c b/ui/keymaps.c
index 78c7ea3..0545d49 100644
--- a/ui/keymaps.c
+++ b/ui/keymaps.c
@@ -146,7 +146,7 @@ static kbd_layout_t *parse_keyboard_layout(const name2keysym_t *table,
 		    if (rest && strstr(rest, "addupper")) {
 			char *c;
 			for (c = line; *c; c++)
-			    *c = toupper(*c);
+			    *c = qemu_toupper(*c);
 			keysym = get_keysym(table, line);
 			if (keysym)
 			    add_keysym(line, keysym, keycode | SCANCODE_SHIFT, k);