diff --git a/.builder/actions/tls_server_setup.py b/.builder/actions/tls_server_setup.py
index dbbd9c6f4..46b5db848 100644
--- a/.builder/actions/tls_server_setup.py
+++ b/.builder/actions/tls_server_setup.py
@@ -59,6 +59,7 @@ def run(self, env):
                                "-connect", "127.0.0.1:59443",
                                "-key", "unittests.key",
                                "-cert", "unittests.crt",
+                               "-CAfile", "ca_root.crt",
                                "-tls1_3",
                                ], cwd=dir, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
         p2.poll()