1 files changed, 1 insertions, 0 deletions
diff --git a/internal.h b/internal.h
index f26a63dbf6..ad710d08d8 100644
--- a/internal.h
+++ b/internal.h
@@ -435,6 +435,7 @@ void rb_gc_writebarrier_remember_promoted(VALUE obj);
 /* hash.c */
 struct st_table *rb_hash_tbl_raw(VALUE hash);
 #define RHASH_TBL_RAW(h) rb_hash_tbl_raw(h)
+VALUE rb_hash_keys(VALUE hash);
 
 /* inits.c */
 void rb_call_inits(void);