1 files changed, 1 insertions, 1 deletions
diff --git a/hash.c b/hash.c
index 87f51284de..0072852a82 100644
--- a/hash.c
+++ b/hash.c
@@ -2399,7 +2399,7 @@ static VALUE rb_hash_compare_by_id_p(VALUE hash);
  *     h1["a"]        #=> 100
  *     h1.compare_by_identity
  *     h1.compare_by_identity? #=> true
- *     h1["a"]        #=> nil  # different objects.
+ *     h1["a".dup]    #=> nil  # different objects.
  *     h1[:c]         #=> "c"  # same symbols are all same.
  *
  */