diff --git a/htdocs/core/modules/mrp/mod_mo_advanced.php b/htdocs/core/modules/mrp/mod_mo_advanced.php
index 186caca619a..592dd23388e 100644
--- a/htdocs/core/modules/mrp/mod_mo_advanced.php
+++ b/htdocs/core/modules/mrp/mod_mo_advanced.php
@@ -68,7 +68,7 @@ class mod_mo_advanced extends ModeleNumRefMos
 		$texte .= '<form action="'.$_SERVER["PHP_SELF"].'" method="POST">';
 		$texte .= '<input type="hidden" name="token" value="'.newToken().'">';
 		$texte .= '<input type="hidden" name="action" value="updateMask">';
-		$texte .= '<input type="hidden" name="maskconstBom" value="MRP_MO_ADVANCED_MASK">';
+		$texte .= '<input type="hidden" name="maskconstMo" value="MRP_MO_ADVANCED_MASK">';
 		$texte .= '<table class="nobordernopadding" width="100%">';
 
 		$tooltip = $langs->trans("GenericMaskCodes", $langs->transnoentities("Mo"), $langs->transnoentities("Mo"));