diff --git a/src/Planning.php b/src/Planning.php
index 5804d7b78a6..bdd9c47dcd1 100644
--- a/src/Planning.php
+++ b/src/Planning.php
@@ -1313,7 +1313,7 @@ public static function showAddGroupUsersForm()
     {
         echo Group::getTypeName(1) . " : <br>";
 
-        $condition = ['is_task' => 1];
+        $condition = [];
        // filter groups
         if (!Session::haveRight('planning', self::READALL)) {
             $condition['id'] = $_SESSION['glpigroups'];