diff --git a/inc/traduire.php b/inc/traduire.php
index e171c6fbad928d153bdb0ddb219b4120d15464ce..3c22b4e1a2a522b5c2008800d3158c351cdee1b0 100644
--- a/inc/traduire.php
+++ b/inc/traduire.php
@@ -149,6 +149,7 @@ function lire_fichier_langue(string $fichier): array {
 	$GLOBALS['idx_lang'] = $idx_lang_before;
 	if (!is_array($idx_lang)) {
 		if (isset($GLOBALS[$idx_lang_tmp]) && is_array($GLOBALS[$idx_lang_tmp])) {
+			trigger_deprecation('spip', '5.0', sprintf('Lang file "%s" populating a GLOBALS is deprecated. Return an array instead.', $fichier));
 			$idx_lang = $GLOBALS[$idx_lang_tmp];
 		} else {
 			$idx_lang = [];