diff --git a/tests/Makefile.am b/tests/Makefile.am
index 130bdba3..181a5aa7 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -80,7 +80,7 @@ TESTS = $(check_SCRIPTS)
 test: check
 
 test-regression: run-regression-tests.pl
-	$(PERL) run-regression-tests.pl
+	$(PERL) run-regression-tests.pl -S .
 
 test-regression-nginx: run-regression-tests-nginx.pl
 	$(PERL) run-regression-tests-nginx.pl