diff --git a/src/Persister/PdoPersister.php b/src/Persister/PdoPersister.php
index f51395f..5d077bd 100644
--- a/src/Persister/PdoPersister.php
+++ b/src/Persister/PdoPersister.php
@@ -157,7 +157,7 @@ public function find($class, $id)
     private function implodeFieldsNames($fields)
     {
         $fields_names = array_keys($fields);
-        return "`" . implode($fields_names, "`, `") . "`";
+        return "`" . implode("`, `", $fields_names) . "`";
     }
 
     public function getExpectedSqlQuery($sql, $fields)