diff --git a/pyproject.toml b/pyproject.toml
index c8899d768..7a486d273 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -67,7 +67,7 @@ dependencies = [
     # DARTLAB_CROSS_SCAN_ENGINE=duckdb 또는 large dataset 검출 시 자동 fallback.
     "duckdb>=1.0,<2; sys_platform != 'emscripten'",
     "cryptography>=46,<51; sys_platform != 'emscripten'",
-    "filelock>=3.20,<4; sys_platform != 'emscripten'",
+    "filelock>=3.20,<5; sys_platform != 'emscripten'",
     "keyring>=25.7,<26; sys_platform != 'emscripten' and sys_platform != 'win32'",
     "numpy>=1.26.0,<3; sys_platform != 'emscripten'",
     "numpy; sys_platform == 'emscripten'",