diff --git a/htdocs/comm/action/fiche.php b/htdocs/comm/action/fiche.php
index d1255d6f2f9..f94dfec4369 100644
--- a/htdocs/comm/action/fiche.php
+++ b/htdocs/comm/action/fiche.php
@@ -71,6 +71,9 @@ if ($_POST["action"] == 'add_action')
                    $_POST["admonth"],
                    $_POST["adday"],
                    $_POST["adyear"]);
+	// Si param incorrects, mktime renvoi false en PHP 5.1, -1 avant
+	if (! $datep > 0) $datep='';
+	if (! $datea > 0) $datea='';
 
     if ($_POST["contactid"])
     {