diff --git a/forms/ComplexTableField.php b/forms/ComplexTableField.php
index f4f29b705..fca82d7f5 100755
--- a/forms/ComplexTableField.php
+++ b/forms/ComplexTableField.php
@@ -392,7 +392,7 @@ JS;
 		// we can't rely on $idField being populated, and fall back to the request-params.
 		// this is a workaround for a bug where each subsequent popup-call didn't have ID
 		// of the parent set, and so didn't properly save the relation
-		return ($idField->Value()) ? $idField->Value() : $_REQUEST['ctf']['ID'];
+		return ($idField->Value()) ? $idField->Value() : (isset($_REQUEST['ctf']['ID']) ? $_REQUEST['ctf']['ID'] : null);
  	}