diff --git a/eth/package-lock.json b/eth/package-lock.json
index 975f0d3..431127c 100644
--- a/eth/package-lock.json
+++ b/eth/package-lock.json
@@ -9,15 +9,15 @@
       "version": "0.0.1",
       "license": "GPL-3.0-or-later",
       "devDependencies": {
-        "@openzeppelin/contracts": "^4.4.2",
+        "@openzeppelin/contracts": "^4.9.1",
         "@poanet/solidity-flattener": "^3.0.6",
         "sol-merger": "^3.1.0"
       }
     },
     "node_modules/@openzeppelin/contracts": {
-      "version": "4.4.2",
-      "resolved": "https://registry.npmjs.org/@openzeppelin/contracts/-/contracts-4.4.2.tgz",
-      "integrity": "sha512-NyJV7sJgoGYqbtNUWgzzOGW4T6rR19FmX1IJgXGdapGPWsuMelGJn9h03nos0iqfforCbCB0iYIR0MtIuIFLLw==",
+      "version": "4.9.1",
+      "resolved": "https://registry.npmjs.org/@openzeppelin/contracts/-/contracts-4.9.1.tgz",
+      "integrity": "sha512-aLDTLu/If1qYIFW5g4ZibuQaUsFGWQPBq1mZKp/txaebUnGHDmmiBhRLY1tDNedN0m+fJtKZ1zAODS9Yk+V6uA==",
       "dev": true
     },
     "node_modules/@poanet/solidity-flattener": {
@@ -639,9 +639,9 @@
   },
   "dependencies": {
     "@openzeppelin/contracts": {
-      "version": "4.4.2",
-      "resolved": "https://registry.npmjs.org/@openzeppelin/contracts/-/contracts-4.4.2.tgz",
-      "integrity": "sha512-NyJV7sJgoGYqbtNUWgzzOGW4T6rR19FmX1IJgXGdapGPWsuMelGJn9h03nos0iqfforCbCB0iYIR0MtIuIFLLw==",
+      "version": "4.9.1",
+      "resolved": "https://registry.npmjs.org/@openzeppelin/contracts/-/contracts-4.9.1.tgz",
+      "integrity": "sha512-aLDTLu/If1qYIFW5g4ZibuQaUsFGWQPBq1mZKp/txaebUnGHDmmiBhRLY1tDNedN0m+fJtKZ1zAODS9Yk+V6uA==",
       "dev": true
     },
     "@poanet/solidity-flattener": {
diff --git a/eth/package.json b/eth/package.json
index e9e0ec5..f6fad8a 100644
--- a/eth/package.json
+++ b/eth/package.json
@@ -12,7 +12,7 @@
   "author": "nahkd123",
   "license": "GPL-3.0-or-later",
   "devDependencies": {
-    "@openzeppelin/contracts": "^4.4.2",
+    "@openzeppelin/contracts": "^4.9.1",
     "@poanet/solidity-flattener": "^3.0.6",
     "sol-merger": "^3.1.0"
   }