diff --git a/nixos/tests/roundcube.nix b/nixos/tests/roundcube.nix
index fd9c72915943..48e7fa59b4ef 100644
--- a/nixos/tests/roundcube.nix
+++ b/nixos/tests/roundcube.nix
@@ -33,6 +33,6 @@
     roundcube.wait_for_unit("postgresql.target")
     roundcube.wait_for_unit("phpfpm-roundcube.service")
     roundcube.wait_for_unit("nginx.service")
-    roundcube.succeed("curl -sSfL http://roundcube/ | grep 'Keep me logged in'")
+    t.assertIn("Keep me logged in", roundcube.succeed("curl -sSfL http://roundcube/"))
   '';
 }