1 files changed, 9 insertions, 0 deletions
diff --git a/hash.c b/hash.c
index 75c07797d3..b2a17698df 100644
--- a/hash.c
+++ b/hash.c
@@ -41,6 +41,14 @@ rb_hash_freeze(hash)
     return rb_obj_freeze(hash);
 }
 
+static VALUE
+rb_hash_frozen_p(hash)
+    VALUE hash;
+{
+    if (OBJ_FROZEN(hash)) return Qtrue;
+    return Qfalse;
+}
+
 VALUE rb_cHash;
 
 static VALUE envtbl;
@@ -1789,6 +1797,7 @@ Init_Hash()
     rb_define_method(rb_cHash,"to_a", rb_hash_to_a, 0);
     rb_define_method(rb_cHash,"to_s", rb_hash_to_s, 0);
     rb_define_method(rb_cHash,"inspect", rb_hash_inspect, 0);
+    rb_define_method(rb_cHash,"frozen?", rb_hash_frozen_p, 0);
 
     rb_define_method(rb_cHash,"==", rb_hash_equal, 1);
     rb_define_method(rb_cHash,"[]", rb_hash_aref, 1);