diff --git a/spec/ruby/core/dir/shared/open.rb b/spec/ruby/core/dir/shared/open.rb
index 6df361e452..63e9036053 100644
--- a/spec/ruby/core/dir/shared/open.rb
+++ b/spec/ruby/core/dir/shared/open.rb
@@ -65,6 +65,7 @@ describe :dir_open, shared: true do
     it 'sets the close-on-exec flag for the directory file descriptor' do
       Dir.send(@method, DirSpecs.mock_dir) do |dir|
         io = IO.for_fd(dir.fileno)
+        io.autoclose = false
         io.close_on_exec?.should == true
       end
     end
diff --git a/spec/ruby/core/process/spawn_spec.rb b/spec/ruby/core/process/spawn_spec.rb
index 43e389ad7f..bbc8ceb1da 100644
--- a/spec/ruby/core/process/spawn_spec.rb
+++ b/spec/ruby/core/process/spawn_spec.rb
@@ -582,7 +582,7 @@ describe "Process.spawn" do
           r.close_on_exec = false
           w.close_on_exec = false
 
-          code = "fd = IO.for_fd(#{w.fileno}); fd.write 'abc'; fd.close"
+          code = "fd = IO.for_fd(#{w.fileno}); fd.autoclose = false; fd.write 'abc'; fd.close"
           pid = Process.spawn(ruby_cmd(code), @options)
           begin
             w.close