diff --git a/src/Illuminate/Filesystem/Filesystem.php b/src/Illuminate/Filesystem/Filesystem.php
index ef732991d867..23fc17eeb03c 100644
--- a/src/Illuminate/Filesystem/Filesystem.php
+++ b/src/Illuminate/Filesystem/Filesystem.php
@@ -268,11 +268,12 @@ public function prepend($path, $data)
      *
      * @param  string  $path
      * @param  string  $data
+     * @param  bool  $lock
      * @return int
      */
-    public function append($path, $data)
+    public function append($path, $data, $lock = false)
     {
-        return file_put_contents($path, $data, FILE_APPEND);
+        return file_put_contents($path, $data, FILE_APPEND | ($lock ? LOCK_EX : 0));
     }
 
     /**
diff --git a/src/Illuminate/Support/Facades/File.php b/src/Illuminate/Support/Facades/File.php
index 8fa9aee26b6d..a1ade8789643 100755
--- a/src/Illuminate/Support/Facades/File.php
+++ b/src/Illuminate/Support/Facades/File.php
@@ -16,7 +16,7 @@
  * @method static void replace(string $path, string $content, int|null $mode = null)
  * @method static void replaceInFile(array|string $search, array|string $replace, string $path)
  * @method static int prepend(string $path, string $data)
- * @method static int append(string $path, string $data)
+ * @method static int append(string $path, string $data, bool $lock = false)
  * @method static mixed chmod(string $path, int|null $mode = null)
  * @method static bool delete(string|array $paths)
  * @method static bool move(string $path, string $target)