diff --git a/test/irb/test_debug_cmd.rb b/test/irb/test_debug_cmd.rb
index 5033431a02..0242baa261 100644
--- a/test/irb/test_debug_cmd.rb
+++ b/test/irb/test_debug_cmd.rb
@@ -223,6 +223,9 @@ module TestIRB
             end
           end
         end
+      ensure
+        read.close
+        write.close
       end
 
       lines.join