diff --git a/tests/external.nix b/tests/external.nix
index 0f51d46..a65f0ce 100644
--- a/tests/external.nix
+++ b/tests/external.nix
@@ -503,6 +503,11 @@
           server.fail("journalctl -u postfix | grep -i warning >&2")
           server.fail("journalctl -u dovecot2 | grep -v 'imap-login: Debug: SSL error: Connection closed' | grep -i error >&2")
           # harmless ? https://dovecot.org/pipermail/dovecot/2020-August/119575.html
-          server.fail("journalctl -u dovecot2 | grep -v 'Expunged message reappeared, giving a new UID' | grep -i warning >&2")
+          server.fail(
+            "journalctl -u dovecot2 | \
+              grep -v 'Expunged message reappeared, giving a new UID' | \
+              grep -v 'Time moved forwards' | \
+              grep -i warning >&2"
+          )
     '';
 }