diff --git a/grub-core/script/lexer.c b/grub-core/script/lexer.c
index 5fb0cbd0b..57778f881 100644
--- a/grub-core/script/lexer.c
+++ b/grub-core/script/lexer.c
@@ -346,7 +346,7 @@ grub_script_yylex (union YYSTYPE *value,
 }
 
 void
-grub_script_yyerror (struct grub_parser_param *state, char const *err)
+grub_script_yyerror (struct grub_parser_param *state, const char *err)
 {
   if (err)
     grub_error (GRUB_ERR_INVALID_COMMAND, err);
diff --git a/include/grub/script_sh.h b/include/grub/script_sh.h
index 6c48e0751..e5b4d8450 100644
--- a/include/grub/script_sh.h
+++ b/include/grub/script_sh.h
@@ -318,7 +318,7 @@ void *grub_script_malloc (struct grub_parser_param *state, grub_size_t size);
 union YYSTYPE;
 int grub_script_yylex (union YYSTYPE *, struct grub_parser_param *);
 int grub_script_yyparse (struct grub_parser_param *);
-void grub_script_yyerror (struct grub_parser_param *, char const *);
+void grub_script_yyerror (struct grub_parser_param *, const char *);
 
 /* Commands to execute, don't use these directly.  */
 grub_err_t grub_script_execute_cmdline (struct grub_script_cmd *cmd);