diff --git a/packages/oo7-substrate/package.json b/packages/oo7-substrate/package.json
index 35aa346..57b3134 100644
--- a/packages/oo7-substrate/package.json
+++ b/packages/oo7-substrate/package.json
@@ -23,7 +23,7 @@
   },
   "homepage": "https://github.com/paritytech/oo7/tree/master/packages/oo7-substrate#readme",
   "dependencies": {
-    "@polkadot/util": "^0.41.1",
+    "@polkadot/util": "^0.75.1",
     "@polkadot/wasm-crypto": "^0.5.1",
     "@polkadot/wasm-schnorrkel": "^0.3.1",
     "base-x": "^3.0.4",
diff --git a/packages/oo7-substrate/yarn.lock b/packages/oo7-substrate/yarn.lock
index 4a36e9e..90c80c0 100644
--- a/packages/oo7-substrate/yarn.lock
+++ b/packages/oo7-substrate/yarn.lock
@@ -9,10 +9,10 @@
   dependencies:
     regenerator-runtime "^0.13.2"
 
-"@polkadot/util@^0.41.1":
-  version "0.41.1"
-  resolved "https://registry.yarnpkg.com/@polkadot/util/-/util-0.41.1.tgz#b67762a0a7408138d843adc7240944e704e819e7"
-  integrity sha512-1mFHxxdXyRgeFk0ygfJklzsf6HiEEMikrpUgr+3Dw5S7KromjPD8EbWkpcZQZ3Png5PTwGyjrx7MYY4Ajiu5xQ==
+"@polkadot/util@^0.75.1":
+  version "0.75.1"
+  resolved "https://registry.yarnpkg.com/@polkadot/util/-/util-0.75.1.tgz#f1719b7ac416e73d0683e443498b9693d7ac42f4"
+  integrity sha512-rXd8J6MR0MLFoi1duddUNL0ftKBtpuysgxUU4hGuVq335jS7xqNAV//nwwLXSLCsOkd3rlLJSz6mxbFXH/PfrQ==
   dependencies:
     "@babel/runtime" "^7.4.0"
     "@types/bn.js" "^4.11.4"
@@ -522,10 +522,10 @@ once@^1.3.0:
   dependencies:
     wrappy "1"
 
-oo7@^0.7.10:
-  version "0.7.10"
-  resolved "https://registry.yarnpkg.com/oo7/-/oo7-0.7.10.tgz#5ecc2b76f04f585679ffe13f1e3ab527389b700c"
-  integrity sha512-jUCFP0gxyjDyjuxd6/CfuY7tQ63dKJNWdO/V8hjyAAXUHPGNL2CmMJOa/2TysR+E/L7Ha8UXZ6xUiOunbrejSw==
+oo7@^0.7.12:
+  version "0.7.12"
+  resolved "https://registry.yarnpkg.com/oo7/-/oo7-0.7.12.tgz#bd7a01ba4e815c1fcde9bea2a9a8226d06ec781e"
+  integrity sha512-nVmxwLIiVCY4Aid6/+p2ujJ2mj3yh15zQ3xSl3UPui7U37DJJfD0KmuMjp+XOWH1HxTkKhIKDgR34eEhFHNxgA==
 
 param-case@^2.1.0:
   version "2.1.1"