1 files changed, 3 insertions, 0 deletions
diff --git a/internal.h b/internal.h
index 5b66192ddf..9bf66c2780 100644
--- a/internal.h
+++ b/internal.h
@@ -87,6 +87,9 @@ ID rb_id_encoding(void);
 /* encoding.c */
 void rb_gc_mark_encodings(void);
 
+/* enum.c */
+VALUE enum_cycle_size(VALUE self, VALUE args);
+
 /* error.c */
 NORETURN(PRINTF_ARGS(void rb_compile_bug(const char*, int, const char*, ...), 3, 4));
 VALUE rb_check_backtrace(VALUE);