diff --git a/src/Sql/Data.php b/src/Sql/Data.php
index f5463f0..acd6ade 100644
--- a/src/Sql/Data.php
+++ b/src/Sql/Data.php
@@ -223,7 +223,7 @@ public function serialize(array $data, mixed $omit = null, bool $nullEmpty = fal
 
         // Force UPDATE SQL
         if (($this->forceUpdate) && !empty($this->conflictKey)) {
-            foreach ($data as $i => $row) {
+            foreach ($data as $row) {
                 $primaryValue = $row[$this->conflictKey];
                 unset($row[$this->conflictKey]);