diff --git a/pyproject.toml b/pyproject.toml
index b5a6326..cc08b0d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -19,7 +19,7 @@ Documentation = "https://waio.readthedocs.io/"
 [tool.poetry.dependencies]
 python = "^3.6"
 aiohttp = "^3.7.4.post0"
-ujson = "5.2.0"
+ujson = "5.4.0"
 dataclass-factory = "^2.11"
 loguru = "^0.5.3"
 aioredis = "2.0.0"