diff --git a/ChangeLog b/ChangeLog
index 1c44cd8c00..6e200e97d0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Wed Dec  9 16:10:37 2015  Koichi Sasada  <ko1@atdot.net>
+
+	* vm.c (rb_vm_cref_in_context): Module#define_method in non-class
+	  expression should be public.
+	  [Bug #11754]
+
+	* test/ruby/test_method.rb: add a test.
+
 Wed Dec  9 15:48:12 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* regcomp.c (onig_chain_link_add): use atomic operation instead of
diff --git a/test/ruby/test_method.rb b/test/ruby/test_method.rb
index 9e20d5cc22..48178c4d7a 100644
--- a/test/ruby/test_method.rb
+++ b/test/ruby/test_method.rb
@@ -924,6 +924,8 @@ class TestMethod < Test::Unit::TestCase
     def m1
       def m2
       end
+
+      self.class.send(:define_method, :m3){} # [Bug #11754]
     end
     private
   end
@@ -933,7 +935,7 @@ class TestMethod < Test::Unit::TestCase
     assert_equal([].sort, MethodInMethodClass.private_instance_methods(false).sort)
 
     MethodInMethodClass.new.m1
-    assert_equal([:m1, :m2].sort, MethodInMethodClass.public_instance_methods(false).sort)
+    assert_equal([:m1, :m2, :m3].sort, MethodInMethodClass.public_instance_methods(false).sort)
     assert_equal([].sort, MethodInMethodClass.private_instance_methods(false).sort)
   end
 end
diff --git a/vm.c b/vm.c
index 23be295fef..b83595db36 100644
--- a/vm.c
+++ b/vm.c
@@ -1226,6 +1226,7 @@ rb_vm_cref_in_context(VALUE self, VALUE cbase)
     const rb_control_frame_t *cfp = rb_vm_get_ruby_level_next_cfp(th, th->cfp);
     const rb_cref_t *cref;
     if (cfp->self != self) return NULL;
+    if (!vm_env_cref_by_cref(cfp->ep)) return NULL;
     cref = rb_vm_get_cref(cfp->ep);
     if (CREF_CLASS(cref) != cbase) return NULL;
     return cref;