diff --git a/test/excludes/TestThread.rb b/test/excludes/TestThread.rb
index ea7269f7c4..0b4050b4eb 100644
--- a/test/excludes/TestThread.rb
+++ b/test/excludes/TestThread.rb
@@ -1 +1 @@
-exclude /_stack_size$/, 'often too expensive'
+exclude(/_stack_size$/, 'often too expensive')