diff --git a/package.json b/package.json
index 8b20bf3..3a4d591 100644
--- a/package.json
+++ b/package.json
@@ -8,7 +8,7 @@
     },
     "license": "MIT",
     "dependencies": {
-        "@openzeppelin/contracts": "^3.3.0"
+        "@openzeppelin/contracts": "^4.9.6"
     },
     "devDependencies": {
         "solc": "^0.6.12",
diff --git a/yarn.lock b/yarn.lock
index 27fb8e7..649f983 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -818,10 +818,10 @@
   resolved "https://registry.yarnpkg.com/@noble/hashes/-/hashes-1.4.0.tgz#45814aa329f30e4fe0ba49426f49dfccdd066426"
   integrity sha512-V1JJ1WTRUqHHrOSh597hURcMqVKVGL/ea3kv0gSnEdsEZ0/+VyPghM1lMNGc00z7CIQorSvbKpuJkxvuHbvdbg==
 
-"@openzeppelin/contracts@^3.3.0":
-  version "3.4.2"
-  resolved "https://registry.yarnpkg.com/@openzeppelin/contracts/-/contracts-3.4.2.tgz#d81f786fda2871d1eb8a8c5a73e455753ba53527"
-  integrity sha512-z0zMCjyhhp4y7XKAcDAi3Vgms4T2PstwBdahiO0+9NaGICQKjynK3wduSRplTgk4LXmoO1yfDGO5RbjKYxtuxA==
+"@openzeppelin/contracts@^4.9.6":
+  version "4.9.6"
+  resolved "https://registry.yarnpkg.com/@openzeppelin/contracts/-/contracts-4.9.6.tgz#2a880a24eb19b4f8b25adc2a5095f2aa27f39677"
+  integrity sha512-xSmezSupL+y9VkHZJGDoCBpmnB2ogM13ccaYDWqJTfS3dbuHkgjuwDFUmaFauBCboQMGB/S5UqUl2y54X99BmA==
 
 "@protobufjs/aspromise@^1.1.1", "@protobufjs/aspromise@^1.1.2":
   version "1.1.2"