diff --git a/test/test_rake_application.rb b/test/test_rake_application.rb
index daa4a57ba..e3bc43842 100644
--- a/test/test_rake_application.rb
+++ b/test/test_rake_application.rb
@@ -351,9 +351,9 @@ def test_terminal_columns
     assert_equal 42, app.terminal_columns
   ensure
     if old_rake_columns
-      ENV['RAKE_COLUMNS'].delete
-    else
       ENV['RAKE_COLUMNS'] = old_rake_columns
+    else
+      ENV.delete 'RAKE_COLUMNS'
     end
   end