diff --git a/packages/oo7-substrate/yarn.lock b/packages/oo7-substrate/yarn.lock
index 8c3f3eb..2bef6eb 100644
--- a/packages/oo7-substrate/yarn.lock
+++ b/packages/oo7-substrate/yarn.lock
@@ -132,9 +132,9 @@ bs58@^4.0.1:
     base-x "^3.0.2"
 
 buffer@^5.2.1:
-  version "5.2.1"
-  resolved "https://registry.yarnpkg.com/buffer/-/buffer-5.2.1.tgz#dd57fa0f109ac59c602479044dca7b8b3d0b71d6"
-  integrity sha512-c+Ko0loDaFfuPWiL02ls9Xd3GO3cPVmUobQ6t3rXNUk304u6hGq+8N/kFi+QEIKhzK3uwolVhLzszmfLmMLnqg==
+  version "5.4.0"
+  resolved "https://registry.yarnpkg.com/buffer/-/buffer-5.4.0.tgz#33294f5c1f26e08461e528b69fa06de3c45cbd8c"
+  integrity sha512-Xpgy0IwHK2N01ncykXTy6FpCWuM+CJSHoPVBLyNqyrWxsedpLvwsYUhf0ME3WRFNUhos0dMamz9cOS/xRDtU5g==
   dependencies:
     base64-js "^1.0.2"
     ieee754 "^1.1.4"