diff --git a/tests/tests_test.go b/tests/tests_test.go
index e84162cd..e1b33ea7 100644
--- a/tests/tests_test.go
+++ b/tests/tests_test.go
@@ -1,3 +1,4 @@
+//go:debug x509negativeserial=1
 package tests_test
 
 import (