diff --git a/lib/Client.php b/lib/Client.php
index 1bd92b6..1881c82 100644
--- a/lib/Client.php
+++ b/lib/Client.php
@@ -117,15 +117,15 @@ class Client
 		return $db->update('plugin_facturation_clients', $data, $db->where('id', (int)$id));
 	}
 
-	public function isDeletable($id)
+	public function isDeletable($id): bool
 	{
 		$f = new Facture;
-		return $f->hasDocs(0, $id);
+		return !$f->hasDocs(0, $id);
 	}
 
 	public function delete($id)
 	{
-		if($this->isDeletable($id))
+		if(!$this->isDeletable($id))
 		{
 			return false;
 		}