diff --git a/lex.c.blt b/lex.c.blt
--- a/lex.c.blt
+++ b/lex.c.blt
@@ -31,7 +31,7 @@
 #line 1 "keywords"
 
 struct kwtable {const char *name; int id[2]; enum lex_state_e state;};
-const struct kwtable *rb_reserved_word(const char *, unsigned int);
+static const struct kwtable *rb_reserved_word(const char *, unsigned int);
 #ifndef RIPPER
 #line 7 "keywords"
 struct kwtable;
@@ -105,7 +105,7 @@
 __attribute__ ((__gnu_inline__))
 #endif
 #endif
-const struct kwtable *
+static const struct kwtable *
 rb_reserved_word (str, len)
      register const char *str;
      register unsigned int len;