diff --git a/merkle/package.json b/merkle/package.json
index c958835..e74976b 100644
--- a/merkle/package.json
+++ b/merkle/package.json
@@ -26,7 +26,7 @@
     "truffle-assertions": "^0.9.2"
   },
   "dependencies": {
-    "@openzeppelin/contracts": "^3.1.0",
+    "@openzeppelin/contracts": "^4.7.2",
     "@truffle/hdwallet-provider": "^1.0.29",
     "bn.js": "^4.11.0",
     "ethereumjs-util": "^7.0.4",
diff --git a/merkle/yarn.lock b/merkle/yarn.lock
index 7145882..b6ed753 100644
--- a/merkle/yarn.lock
+++ b/merkle/yarn.lock
@@ -232,10 +232,10 @@
     fs-extra "^8.1.0"
     try-require "^1.2.1"
 
-"@openzeppelin/contracts@^3.1.0":
-  version "3.1.0"
-  resolved "https://registry.yarnpkg.com/@openzeppelin/contracts/-/contracts-3.1.0.tgz#bcea457ef89069fbe5a617f50b25b6a8272895d5"
-  integrity sha512-dVXDnUKxrAKLzPdCRkz+N8qsVkK1XxJ6kk3zuI6zaQmcKxN7CkizoDP7lXxcs/Mi2I0mxceTRjJBqlzFffLJrQ==
+"@openzeppelin/contracts@^4.7.2":
+  version "4.7.2"
+  resolved "https://registry.yarnpkg.com/@openzeppelin/contracts/-/contracts-4.7.2.tgz#7587416fe2d35abf574193515b8971bfe9f64bc7"
+  integrity sha512-4n/JL9izql8303mPqPdubuna/DWEMbmOzWYUWyCPhjhiEr2w3nQrjE7vZz1fBF+wzzP6dZbIcsgqACk53c9FGA==
 
 "@openzeppelin/test-helpers@^0.5.6":
   version "0.5.6"