1 files changed, 1 insertions, 0 deletions
diff --git a/array.c b/array.c
index fcbb7d4c30..bcdd29abf1 100644
--- a/array.c
+++ b/array.c
@@ -2080,6 +2080,7 @@ rb_ary_slice_bang(argc, argv, ary)
     VALUE arg1, arg2;
     long pos, len, orig_len;
 
+    rb_ary_modify_check(ary);
     if (rb_scan_args(argc, argv, "11", &arg1, &arg2) == 2) {
 	pos = NUM2LONG(arg1);
 	len = NUM2LONG(arg2);