2 files changed, 15 insertions, 4 deletions
diff --git a/enum.c b/enum.c
index 30f374ad7b..b4cddec9bc 100644
--- a/enum.c
+++ b/enum.c
@@ -1743,6 +1743,9 @@ enum_sort_by(VALUE obj)
 
 #define ENUMFUNC(name) argc ? name##_eqq : rb_block_given_p() ? name##_iter_i : name##_i
 
+#define ENUM_BLOCK_CALL(name) \
+    rb_block_call2(obj, id_each, 0, 0, ENUMFUNC(name), (VALUE)memo, rb_block_given_p() && rb_block_pair_yield_optimizable() ? RB_BLOCK_NO_USE_PACKED_ARGS : 0);
+
 #define MEMO_ENUM_NEW(v1) (rb_check_arity(argc, 0, 1), MEMO_NEW((v1), (argc ? *argv : 0), 0))
 
 #define DEFINE_ENUMFUNCS(name) \
@@ -1836,7 +1839,7 @@ enum_all(int argc, VALUE *argv, VALUE obj)
 {
     struct MEMO *memo = MEMO_ENUM_NEW(Qtrue);
     WARN_UNUSED_BLOCK(argc);
-    rb_block_call2(obj, id_each, 0, 0, ENUMFUNC(all), (VALUE)memo, RB_BLOCK_NO_USE_PACKED_ARGS);
+    ENUM_BLOCK_CALL(all);
     return memo->v1;
 }
 
@@ -1898,7 +1901,7 @@ enum_any(int argc, VALUE *argv, VALUE obj)
 {
     struct MEMO *memo = MEMO_ENUM_NEW(Qfalse);
     WARN_UNUSED_BLOCK(argc);
-    rb_block_call2(obj, id_each, 0, 0, ENUMFUNC(any), (VALUE)memo, RB_BLOCK_NO_USE_PACKED_ARGS);
+    ENUM_BLOCK_CALL(any);
     return memo->v1;
 }
 
@@ -2187,7 +2190,7 @@ enum_one(int argc, VALUE *argv, VALUE obj)
     VALUE result;
 
     WARN_UNUSED_BLOCK(argc);
-    rb_block_call2(obj, id_each, 0, 0, ENUMFUNC(one), (VALUE)memo, RB_BLOCK_NO_USE_PACKED_ARGS);
+    ENUM_BLOCK_CALL(one);
     result = memo->v1;
     if (UNDEF_P(result)) return Qfalse;
     return result;
@@ -2248,7 +2251,7 @@ enum_none(int argc, VALUE *argv, VALUE obj)
     struct MEMO *memo = MEMO_ENUM_NEW(Qtrue);
 
     WARN_UNUSED_BLOCK(argc);
-    rb_block_call2(obj, id_each, 0, 0, ENUMFUNC(none), (VALUE)memo, RB_BLOCK_NO_USE_PACKED_ARGS);
+    ENUM_BLOCK_CALL(none);
     return memo->v1;
 }
 
diff --git a/test/ruby/test_enum.rb b/test/ruby/test_enum.rb
index 7503e06272..237bdc8a4d 100644
--- a/test/ruby/test_enum.rb
+++ b/test/ruby/test_enum.rb
@@ -1348,4 +1348,12 @@ class TestEnumerable < Test::Unit::TestCase
     klass.new.grep(/(b.)/) { svars << $1 }
     assert_equal(["ba", "ba"], svars)
   end
+
+  def test_all_fast
+    data = { "key" => { "key2" => 1 } }
+    kk = vv = nil
+    data.all? { |(k, v)| kk, vv = k, v }
+    assert_equal(kk, "key")
+    assert_equal(vv, { "key2" => 1 })
+  end
 end