diff --git a/nixos/tests/nginx-http3.nix b/nixos/tests/nginx-http3.nix
index edd0759464c8..319f6aac184a 100644
--- a/nixos/tests/nginx-http3.nix
+++ b/nixos/tests/nginx-http3.nix
@@ -70,6 +70,9 @@ in
   testScript = ''
     start_all()
 
+    server.wait_for_unit("nginx")
+    server.wait_for_open_port(443)
+
     # Check http connections
     client.succeed("curl --verbose --http3 https://acme.test | grep 'Hello World!'")