diff --git a/package.json b/package.json
index 2c5061c0e..010487ef5 100644
--- a/package.json
+++ b/package.json
@@ -30,7 +30,7 @@
   },
   "devDependencies": {
     "@polkadot/api-jsonrpc": "^0.5.5",
-    "@polkadot/dev": "^0.10.1"
+    "@polkadot/dev": "^0.11.1"
   },
   "dependencies": {
     "babel-runtime": "^6.26.0",
diff --git a/src/hex/toBuffer.spec.js b/src/hex/toBuffer.spec.js
index 09c9a2f9e..0d6136a95 100644
--- a/src/hex/toBuffer.spec.js
+++ b/src/hex/toBuffer.spec.js
@@ -5,8 +5,8 @@ const { hexToBuffer } = require('./index');
 describe('hexToBuffer', () => {
   it('returns an empty buffer when null provided', () => {
     expect(
-      hexToBuffer(null).length
-    ).toEqual(0);
+      hexToBuffer(null)
+    ).toHaveLength(0);
   });
 
   it('returns a buffer with the correct values', () => {
diff --git a/src/logger.spec.js b/src/logger.spec.js
index 50ed75b31..f1e627eeb 100644
--- a/src/logger.spec.js
+++ b/src/logger.spec.js
@@ -1,7 +1,5 @@
 // ISC, Copyright 2017 Jaco Greeff
 
-/* global jest */
-
 const { logger } = require('./index');
 
 describe('logger', () => {
@@ -31,7 +29,7 @@ describe('logger', () => {
     });
 
     it('adds the date, type & params', () => {
-      expect(formatted.length).toBe(4);
+      expect(formatted).toHaveLength(4);
     });
   });
 
diff --git a/yarn.lock b/yarn.lock
index e67f8c4d1..0fbf1b00d 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -60,9 +60,9 @@
   dependencies:
     babel-runtime "^6.26.0"
 
-"@polkadot/dev@^0.10.1":
-  version "0.10.1"
-  resolved "https://registry.yarnpkg.com/@polkadot/dev/-/dev-0.10.1.tgz#4c57180413320f0194c340177725f8b8c0ecbffa"
+"@polkadot/dev@^0.11.1":
+  version "0.11.1"
+  resolved "https://registry.yarnpkg.com/@polkadot/dev/-/dev-0.11.1.tgz#1f43103c5bb911a905b626340384e2cffe342bd5"
   dependencies:
     babel-cli "^6.26.0"
     babel-core "^6.26.0"
@@ -83,6 +83,7 @@
     eslint-config-standard-react "^5.0.0"
     eslint-plugin-flowtype "^2.39.1"
     eslint-plugin-import "^2.8.0"
+    eslint-plugin-jest "^21.3.2"
     eslint-plugin-node "^5.2.1"
     eslint-plugin-promise "^3.6.0"
     eslint-plugin-react "^7.4.0"
@@ -92,6 +93,7 @@
     jest "^21.2.1"
     makeshift "^1.1.0"
     mkdirp "^0.5.1"
+    postcss-sass "^0.2.0"
     rimraf "^2.6.2"
     stylelint "^8.2.0"
     stylelint-config-standard "^18.0.0"
@@ -1664,6 +1666,10 @@ eslint-plugin-import@^2.8.0:
     minimatch "^3.0.3"
     read-pkg-up "^2.0.0"
 
+eslint-plugin-jest@^21.3.2:
+  version "21.3.2"
+  resolved "https://registry.yarnpkg.com/eslint-plugin-jest/-/eslint-plugin-jest-21.3.2.tgz#b1cefc05f0fed700eb40185a94d16f6d575d1ef9"
+
 eslint-plugin-node@^5.2.1:
   version "5.2.1"
   resolved "https://registry.yarnpkg.com/eslint-plugin-node/-/eslint-plugin-node-5.2.1.tgz#80df3253c4d7901045ec87fa660a284e32bdca29"
@@ -2131,6 +2137,12 @@ globjoin@^0.1.4:
   version "0.1.4"
   resolved "https://registry.yarnpkg.com/globjoin/-/globjoin-0.1.4.tgz#2f4494ac8919e3767c5cbb691e9f463324285d43"
 
+gonzales-pe@^4.0.3:
+  version "4.2.3"
+  resolved "https://registry.yarnpkg.com/gonzales-pe/-/gonzales-pe-4.2.3.tgz#41091703625433285e0aee3aa47829fc1fbeb6f2"
+  dependencies:
+    minimist "1.1.x"
+
 graceful-fs@^4.1.11, graceful-fs@^4.1.2, graceful-fs@^4.1.4, graceful-fs@^4.1.6:
   version "4.1.11"
   resolved "https://registry.yarnpkg.com/graceful-fs/-/graceful-fs-4.1.11.tgz#0e8bdfe4d1ddb8854d64e04ea7c00e2a026e5658"
@@ -3212,6 +3224,10 @@ minimist@0.0.8:
   version "0.0.8"
   resolved "https://registry.yarnpkg.com/minimist/-/minimist-0.0.8.tgz#857fcabfc3397d2625b8228262e86aa7a011b05d"
 
+minimist@1.1.x:
+  version "1.1.3"
+  resolved "https://registry.yarnpkg.com/minimist/-/minimist-1.1.3.tgz#3bedfd91a92d39016fcfaa1c681e8faa1a1efda8"
+
 minimist@^1.1.1, minimist@^1.1.3, minimist@^1.2.0:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/minimist/-/minimist-1.2.0.tgz#a35008b20f41383eec1fb914f4cd5df79a264284"
@@ -3598,6 +3614,13 @@ postcss-safe-parser@^3.0.1:
   dependencies:
     postcss "^6.0.6"
 
+postcss-sass@^0.2.0:
+  version "0.2.0"
+  resolved "https://registry.yarnpkg.com/postcss-sass/-/postcss-sass-0.2.0.tgz#e55516441e9526ba4b380a730d3a02e9eaa78c7a"
+  dependencies:
+    gonzales-pe "^4.0.3"
+    postcss "^6.0.6"
+
 postcss-scss@^1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/postcss-scss/-/postcss-scss-1.0.2.tgz#ff45cf3354b879ee89a4eb68680f46ac9bb14f94"