diff --git a/tests/legacy/unit/entrees_sorties/flock_sous_repertoire.php b/tests/legacy/unit/entrees_sorties/flock_sous_repertoire.php
index 522a6aeb5d36d33ffe460f2686b465d39b977200..31021fc2b920e152655d85cd28010fcccb3ba09a 100644
--- a/tests/legacy/unit/entrees_sorties/flock_sous_repertoire.php
+++ b/tests/legacy/unit/entrees_sorties/flock_sous_repertoire.php
@@ -16,7 +16,7 @@ require $remonte . 'test.inc';
 
 $ok = true;
 
-$sous_repertoire = 'test' . md5(random_int(0, mt_getrandmax()));
+$sous_repertoire = 'test' . md5(strval(random_int(0, mt_getrandmax())));
 
 include_spip('inc/flock');