diff --git a/src/MushRuby/lex.c b/src/MushRuby/lex.c
index a851447..f2f8396 100644
--- a/src/MushRuby/lex.c
+++ b/src/MushRuby/lex.c
@@ -93,7 +93,7 @@ hash (str, len)
 }
 
 #ifdef __GNUC__
-__inline
+extern __inline
 #endif
 struct kwtable *
 rb_reserved_word (str, len)