diff --git a/package.json b/package.json
index f33a8ac..301fb4d 100644
--- a/package.json
+++ b/package.json
@@ -4,7 +4,7 @@
     "build": "lerna run build"
   },
   "dependencies": {
-    "@openzeppelin/contracts": "^2.5.0",
+    "@openzeppelin/contracts": "^4.4.2",
     "@phala/merkledrop-lib": "^1.0.0",
     "@phala/trezor-provider": "^1.0.34",
     "@pinata/sdk": "^1.1.11",
diff --git a/yarn.lock b/yarn.lock
index 13766db..846610e 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2446,10 +2446,10 @@
   dependencies:
     "@types/node" ">= 8"
 
-"@openzeppelin/contracts@^2.5.0":
-  version "2.5.1"
-  resolved "https://registry.yarnpkg.com/@openzeppelin/contracts/-/contracts-2.5.1.tgz#c76e3fc57aa224da3718ec351812a4251289db31"
-  integrity sha512-qIy6tLx8rtybEsIOAlrM4J/85s2q2nPkDqj/Rx46VakBZ0LwtFhXIVub96LXHczQX0vaqmAueDqNPXtbSXSaYQ==
+"@openzeppelin/contracts@^4.4.2":
+  version "4.4.2"
+  resolved "https://registry.yarnpkg.com/@openzeppelin/contracts/-/contracts-4.4.2.tgz#4e889c9c66e736f7de189a53f8ba5b8d789425c2"
+  integrity sha512-NyJV7sJgoGYqbtNUWgzzOGW4T6rR19FmX1IJgXGdapGPWsuMelGJn9h03nos0iqfforCbCB0iYIR0MtIuIFLLw==
 
 "@pinata/sdk@^1.1.11":
   version "1.1.11"