1 files changed, 2 insertions, 1 deletions
diff --git a/test/ruby/test_process.rb b/test/ruby/test_process.rb
index 5d85ca3a18..0d2bc50b2d 100644
--- a/test/ruby/test_process.rb
+++ b/test/ruby/test_process.rb
@@ -1814,8 +1814,9 @@ class TestProcess < Test::Unit::TestCase
     assert_separately([], "#{<<~"begin;"}\n#{<<~'end;'}")
     begin;
       io = File.open(IO::NULL)
+      io2 = io.dup
       IO.popen("echo") {|f| io.reopen(f)}
-      io.reopen(io.dup)
+      io.reopen(io2)
     end;
   end