diff --git a/src/Illuminate/Database/Eloquent/Builder.php b/src/Illuminate/Database/Eloquent/Builder.php
index 27487ddf26a8..3c904e5fd186 100755
--- a/src/Illuminate/Database/Eloquent/Builder.php
+++ b/src/Illuminate/Database/Eloquent/Builder.php
@@ -628,6 +628,8 @@ public function chunkById($count, callable $callback, $column = null, $alias = n
             }
 
             $lastId = $results->last()->{$alias};
+
+            unset($results);
         } while ($countResults == $count);
 
         return true;