diff --git a/ChangeLog b/ChangeLog
index 87adee9286..f06c010eab 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Fri Aug 21 17:32:42 2015  Koichi Sasada  <ko1@atdot.net>
+
+	* vm_insnhelper.c (vm_invoke_block): we should not expect ci->argc is
+	  stable after invoking a block. [Bug #11451]
+
+	* test/ruby/test_yield.rb: add a test. This test script is given by
+	  Alex Dowad.
+
 Fri Aug 21 06:35:50 2015  Aaron Patterson <tenderlove@ruby-lang.org>
 
 	* test/openssl/test_ssl_session.rb: Fix tests so that they take in to
diff --git a/test/ruby/test_yield.rb b/test/ruby/test_yield.rb
index a24666b6ca..e7d150a08f 100644
--- a/test/ruby/test_yield.rb
+++ b/test/ruby/test_yield.rb
@@ -401,4 +401,28 @@ class TestRubyYieldGen < Test::Unit::TestCase
     end
     assert_equal [m, nil], y.s(m){|a,b|[a,b]}
   end
+
+  def test_block_cached_argc
+    # [Bug #11451]
+    assert_separately([], <<-"end;")
+      class Yielder
+        def each
+          yield :x, :y, :z
+        end
+      end
+      class Getter1
+        include Enumerable
+        def each(&block)
+          Yielder.new.each(&block)
+        end
+      end
+      class Getter2
+        include Enumerable
+        def each
+          Yielder.new.each { |a, b, c, d| yield(a) }
+        end
+      end
+      Getter1.new.map{Getter2.new.each{|x|}}
+    end;
+  end
 end
diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index d0ab1f34c5..a63a3f7758 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -2336,10 +2336,11 @@ vm_invoke_block(rb_thread_t *th, rb_control_frame_t *reg_cfp, rb_call_info_t *ci
     }
     else {
 	VALUE val;
+	int argc = ci->argc;
 	CALLER_SETUP_ARG(th->cfp, ci);
-	val = vm_yield_with_cfunc(th, block, block->self,
-				  ci->argc, STACK_ADDR_FROM_TOP(ci->argc), 0);
-	POPN(ci->argc); /* TODO: should put before C/yield? */
+
+	val = vm_yield_with_cfunc(th, block, block->self, argc, STACK_ADDR_FROM_TOP(argc), 0);
+	POPN(argc); /* TODO: should put before C/yield? */
 	return val;
     }
 }