diff --git a/src/Index/Index.php b/src/Index/Index.php
index 0d61f9ca..e8ec32ac 100644
--- a/src/Index/Index.php
+++ b/src/Index/Index.php
@@ -423,6 +423,10 @@ private function indexDefinition(int $level, array $parts, array &$storage, Defi
      */
     private function removeIndexedDefinition(int $level, array $parts, array &$storage, array &$rootStorage)
     {
+        if (empty($parts)) {
+            return;
+        }
+        
         $part = $parts[$level];
 
         if ($level + 1 === count($parts)) {