diff --git a/ChangeLog b/ChangeLog
index e9cea867b3..51313d084a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+Tue Aug 16 12:27:48 2016  Koichi Sasada  <ko1@atdot.net>
+
+	* gc.c (gc_mark_roots): should mark the VM object itself to mark
+	  singleton class of the VM object.
+	  Before this patch, we only set mark bit for the VM object and
+	  invoke mark function separately.
+	  [Bug #12583]
+
+	* test/ruby/test_gc.rb: add a test.
+
 Tue Aug 16 12:01:35 2016  Naohisa Goto  <ngotogenome@gmail.com>
 
 	* ext/digest/md5/md5ossl.h: Remove excess semicolons.
diff --git a/gc.c b/gc.c
index c1e8cf8fbc..8a345db0cc 100644
--- a/gc.c
+++ b/gc.c
@@ -4642,7 +4642,7 @@ gc_mark_roots(rb_objspace_t *objspace, const char **categoryp)
     MARK_CHECKPOINT("vm");
     SET_STACK_END;
     rb_vm_mark(th->vm);
-    if (th->vm->self) gc_mark_set(objspace, th->vm->self);
+    if (th->vm->self) gc_mark(objspace, th->vm->self);
 
     MARK_CHECKPOINT("finalizers");
     mark_tbl(objspace, finalizer_table);
diff --git a/test/ruby/test_gc.rb b/test/ruby/test_gc.rb
index 0e3ae4bc42..51b17c6f82 100644
--- a/test/ruby/test_gc.rb
+++ b/test/ruby/test_gc.rb
@@ -397,4 +397,11 @@ class TestGc < Test::Unit::TestCase
       GC.enable unless disabled
     end
   end
+
+  def test_vm_object
+    assert_normal_exit <<-'end', '[Bug #12583]'
+      ObjectSpace.each_object{|o| o.singleton_class rescue 0}
+      ObjectSpace.each_object{|o| case o when Module then o.instance_methods end}
+    end
+  end
 end
diff --git a/version.h b/version.h
index 31265388e3..573105f1a2 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.3.2"
 #define RUBY_RELEASE_DATE "2016-08-16"
-#define RUBY_PATCHLEVEL 166
+#define RUBY_PATCHLEVEL 167
 
 #define RUBY_RELEASE_YEAR 2016
 #define RUBY_RELEASE_MONTH 8