Index: test/ruby/test_io.rb
===================================================================
--- test/ruby/test_io.rb	(revision 25672)
+++ test/ruby/test_io.rb	(working copy)
@@ -798,7 +798,14 @@
       print "no" if ok != 2
       print "ok"
     End
-      assert_equal("ok", f.read)
+      begin
+        Timeout.timeout(10) do
+          assert_equal("ok", f.read)
+        end
+      rescue TimeoutError
+        Process.kill(:KILL, f.pid)
+        raise
+      end
     }
   end