1 files changed, 1 insertions, 1 deletions
diff --git a/array.c b/array.c
index 4eeae43391..034aa7fcf0 100644
--- a/array.c
+++ b/array.c
@@ -3338,7 +3338,7 @@ rb_ary_flatten_bang(int argc, VALUE *argv, VALUE ary)
 
     rb_scan_args(argc, argv, "01", &lv);
     if (!NIL_P(lv)) level = NUM2INT(lv);
-    if (level == 0) return ary;
+    if (level == 0) return Qnil;
 
     result = flatten(ary, level, &mod);
     if (mod == 0) return Qnil;