diff --git a/extconf.rb b/extconf.rb
index 824460f..a43db3e 100644
--- a/extconf.rb
+++ b/extconf.rb
@@ -11,6 +11,6 @@ makefile.print <<EOF
 
 test: all
 	@echo running spec...
-	spec spec/therubyracer_spec.rb
+	spec -O spec/spec.opts spec/therubyracer_spec.rb
 EOF
 end