diff --git a/Hopr/package.json b/Hopr/package.json
old mode 100755
new mode 100644
index 05f9075..51b7569
--- a/Hopr/package.json
+++ b/Hopr/package.json
@@ -11,7 +11,7 @@
     "node": "v12"
   },
   "dependencies": {
-    "@openzeppelin/contracts": "^2.4.0"
+    "@openzeppelin/contracts": "^4.7.2"
   },
   "devDependencies": {
     "@openzeppelin/test-helpers": "^0.5.4",
diff --git a/Hopr/yarn.lock b/Hopr/yarn.lock
index c70bed8..e26d11b 100644
--- a/Hopr/yarn.lock
+++ b/Hopr/yarn.lock
@@ -34,10 +34,10 @@
     fs-extra "^8.1.0"
     try-require "^1.2.1"
 
-"@openzeppelin/contracts@^2.4.0":
-  version "2.4.0"
-  resolved "https://registry.yarnpkg.com/@openzeppelin/contracts/-/contracts-2.4.0.tgz#7270f79ed1463370fe6e664d36a779aa4d3ee896"
-  integrity sha512-xeKP59REgow5TPBJh3S9BRIm7DDG+Rz3Nt4ANWGUkjk4305DHpyUD5CyMJ6nd2JMmZuFyx4mjvvlCtSJLRnN6w==
+"@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@^0.5.4":
   version "0.5.4"