diff --git a/src/Ddl/Ddl.php b/src/Ddl/Ddl.php
index 5dd47c1d3231fc08d5f4b3814c1fa5a254c21290..51d5af6e2f85e043949afe83a11f4038294f15a6 100644
--- a/src/Ddl/Ddl.php
+++ b/src/Ddl/Ddl.php
@@ -276,7 +276,7 @@ class Ddl implements \Iterator, \ArrayAccess
     {
         if (null === $positions) {
             $colPosFile = $this->getColumnsPosFile();
-            if (file_exists($colPosFile)) {
+            if ($colPosFile && file_exists($colPosFile)) {
                 $positions = require $colPosFile;
                 if (!is_array($positions)){
                     throw new \exception('Le fichier des positions doit retourner un tableau PHP');