diff --git a/tool/lib/test/unit.rb b/tool/lib/test/unit.rb
index c113e7e4fd..9671df1ad4 100644
--- a/tool/lib/test/unit.rb
+++ b/tool/lib/test/unit.rb
@@ -182,7 +182,7 @@ module Test
         order = options[:test_order]
         if seed = options[:seed]
           order ||= :random
-        elsif order == :random
+        elsif (order ||= :random) == :random
           seed = options[:seed] = rand(0x10000)
           orig_args.unshift "--seed=#{seed}"
         end