diff --git a/packages/forms/src/Components/Select.php b/packages/forms/src/Components/Select.php
index 0d44d2d570..f77d8acc55 100644
--- a/packages/forms/src/Components/Select.php
+++ b/packages/forms/src/Components/Select.php
@@ -1016,7 +1016,7 @@ class Select extends Field implements Contracts\CanDisableOptions, Contracts\Has
                         }
 
                         $query->update([
-                            $relationship->getForeignKeyName() => $record->getKey(),
+                            $relationship->getForeignKeyName() => $record->getAttribute($relationship->getLocalKeyName()),
                         ]);
                     });
                 }