diff --git a/tests/publish.scm b/tests/publish.scm
index a4a52a4efe7985ec620cd0f6633bb5012f80651f..1ed8308076fc1274befdcbe9188c2e4c2dffd247 100644
--- a/tests/publish.scm
+++ b/tests/publish.scm
@@ -464,7 +464,7 @@ (define %gzip-magic-bytes
                                      (lambda (port)
                                        (display "Hello, build log!"
                                                 (current-error-port))
-                                       (display "" port)))))))
+                                       (display #$(random-text) port)))))))
     (build-derivations %store (list drv))
     (let* ((response (http-get
                       (publish-uri (string-append "/log/"