diff --git a/ChangeLog b/ChangeLog
index 851372d96e..84f596e78d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+Tue Aug 16 13:36:00 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 13:29:25 2016  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* lib/rubygems/package.rb: Fixed potential perms issue unpacking of
diff --git a/gc.c b/gc.c
index 5ebb9376d9..51872f26dd 100644
--- a/gc.c
+++ b/gc.c
@@ -4389,7 +4389,7 @@ 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 7ac67c4757..0dad81671b 100644
--- a/test/ruby/test_gc.rb
+++ b/test/ruby/test_gc.rb
@@ -377,4 +377,11 @@ class TestGc < Test::Unit::TestCase
       C.new
     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 d6e8e3e8b7..dab4a96957 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.2.6"
 #define RUBY_RELEASE_DATE "2016-08-16"
-#define RUBY_PATCHLEVEL 349
+#define RUBY_PATCHLEVEL 350
 
 #define RUBY_RELEASE_YEAR 2016
 #define RUBY_RELEASE_MONTH 8