diff --git a/.eslintrc b/.eslintrc
index 159fee387..2269cb98a 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -44,6 +44,7 @@
   },
 
   "rules": {
+    "default-case": 2,
     "import/no-unresolved": ["error", { "commonjs": true }],
     "no-restricted-globals": ["error", "event"],
     "accessor-pairs": 2,
diff --git a/app/scripts/lib/buy-eth-url.js b/app/scripts/lib/buy-eth-url.js
index d4b74fa19..6892364ca 100644
--- a/app/scripts/lib/buy-eth-url.js
+++ b/app/scripts/lib/buy-eth-url.js
@@ -32,8 +32,9 @@ function getBuyEthUrl ({ network, amount, address, service }) {
       return 'https://github.com/kovan-testnet/faucet'
     case 'goerli-faucet':
       return 'https://goerli-faucet.slock.it/'
+    default:
+      throw new Error(`Unknown cryptocurrency exchange or faucet: "${service}"`)
   }
-  throw new Error(`Unknown cryptocurrency exchange or faucet: "${service}"`)
 }
 
 function getDefaultServiceForNetwork (network) {
@@ -48,6 +49,7 @@ function getDefaultServiceForNetwork (network) {
       return 'kovan-faucet'
     case '5':
       return 'goerli-faucet'
+    default:
+      throw new Error(`No default cryptocurrency exchange or faucet for networkId: "${network}"`)
   }
-  throw new Error(`No default cryptocurrency exchange or faucet for networkId: "${network}"`)
 }
diff --git a/app/scripts/lib/ens-ipfs/resolver.js b/app/scripts/lib/ens-ipfs/resolver.js
index a0af263bc..34b1304c1 100644
--- a/app/scripts/lib/ens-ipfs/resolver.js
+++ b/app/scripts/lib/ens-ipfs/resolver.js
@@ -66,5 +66,7 @@ function getRegistryForChainId (chainId) {
     // goerli
     case 5:
       return '0x112234455c3a32fd11230c42e7bccd4a84e02010'
+    default:
+      return null
   }
 }
diff --git a/app/scripts/lib/typed-message-manager.js b/app/scripts/lib/typed-message-manager.js
index 3f5934299..e87704712 100644
--- a/app/scripts/lib/typed-message-manager.js
+++ b/app/scripts/lib/typed-message-manager.js
@@ -163,6 +163,8 @@ module.exports = class TypedMessageManager extends EventEmitter {
         const activeChainId = parseInt(this.networkController.getNetworkState())
         chainId && assert.equal(chainId, activeChainId, `Provided chainId (${chainId}) must match the active chainId (${activeChainId})`)
         break
+      default:
+        assert.fail(`Unknown params.version ${params.version}`)
     }
   }
 
diff --git a/app/scripts/migrations/004.js b/app/scripts/migrations/004.js
index c0cf600c9..a1ae823cd 100644
--- a/app/scripts/migrations/004.js
+++ b/app/scripts/migrations/004.js
@@ -23,6 +23,7 @@ module.exports = {
             type: 'mainnet',
           }
           break
+        // No default
       }
     } catch (_) {}
     return Promise.resolve(safeVersionedData)
diff --git a/development/version-bump.js b/development/version-bump.js
index 66b6baffe..6ae21b782 100644
--- a/development/version-bump.js
+++ b/development/version-bump.js
@@ -40,6 +40,8 @@ function newVersionFrom (manifest, bumpType) {
     case 'patch':
       segments[2] += 1
       break
+    default:
+      throw new Error(`invalid bumpType ${bumpType}`)
   }
 
   return segments.map(String).join('.')
diff --git a/test/e2e/helpers.js b/test/e2e/helpers.js
index 9e12ba8da..27de882eb 100644
--- a/test/e2e/helpers.js
+++ b/test/e2e/helpers.js
@@ -123,6 +123,8 @@ async function loadExtension (driver, extensionId) {
       await driver.get(`moz-extension://${extensionId}/home.html`)
       break
     }
+    default:
+      throw new Error('Unrecognized SELENIUM_BROWSER value')
   }
 }
 
diff --git a/test/unit/app/typed-message-manager.spec.js b/test/unit/app/typed-message-manager.spec.js
index 3db92d4a3..959662b91 100644
--- a/test/unit/app/typed-message-manager.spec.js
+++ b/test/unit/app/typed-message-manager.spec.js
@@ -30,12 +30,12 @@ describe('Typed Message Manager', () => {
           'EIP712Domain': [
             {'name': 'name', 'type': 'string' },
             {'name': 'version', 'type': 'string' },
-            {'name': 'chainId', ' type': 'uint256' },
-            {'name': 'verifyingContract', ' type': 'address' },
+            {'name': 'chainId', 'type': 'uint256' },
+            {'name': 'verifyingContract', 'type': 'address' },
           ],
           'Person': [
             {'name': 'name', 'type': 'string' },
-            {'name': 'wallet', ' type': 'address' },
+            {'name': 'wallet', 'type': 'address' },
           ],
           'Mail': [
             {'name': 'from', 'type': 'Person' },
@@ -64,7 +64,7 @@ describe('Typed Message Manager', () => {
       }),
     }
 
-    typedMessageManager.addUnapprovedMessage(msgParamsV3, 'V3')
+    typedMessageManager.addUnapprovedMessage(msgParamsV3, null, 'V3')
     typedMsgs = typedMessageManager.getUnapprovedMsgs()
     messages = typedMessageManager.messages
     msgId = Object.keys(typedMsgs)[0]
@@ -73,7 +73,7 @@ describe('Typed Message Manager', () => {
   })
 
   it('supports version 1 of signedTypedData', () => {
-    typedMessageManager.addUnapprovedMessage(msgParamsV1, 'V1')
+    typedMessageManager.addUnapprovedMessage(msgParamsV1, null, 'V1')
     assert.equal(messages[messages.length - 1].msgParams.data, msgParamsV1.data)
   })
 
@@ -87,7 +87,7 @@ describe('Typed Message Manager', () => {
 
   it('validates params', function () {
     assert.doesNotThrow(() => {
-      typedMessageManager.validateParams(messages[0])
+      typedMessageManager.validateParams(messages[0].msgParams)
     }, 'Does not throw with valid parameters')
   })
 
diff --git a/test/unit/ui/app/actions.spec.js b/test/unit/ui/app/actions.spec.js
index 9ed21e729..fffc14ab8 100644
--- a/test/unit/ui/app/actions.spec.js
+++ b/test/unit/ui/app/actions.spec.js
@@ -755,7 +755,6 @@ describe('Actions', () => {
         'domain': {
           'name': 'Ether Mainl',
           'version': '1',
-          'chainId': 1,
           'verifyingContract': '0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC',
         },
         'message': {
@@ -773,11 +772,12 @@ describe('Actions', () => {
     }
 
     beforeEach(() => {
-      metamaskController.newUnsignedTypedMessage(msgParamsV3, 'V3')
+      metamaskController.newUnsignedTypedMessage(msgParamsV3, null, 'V3')
       messages = metamaskController.typedMessageManager.getUnapprovedMsgs()
       typedMessages = metamaskController.typedMessageManager.messages
       msgId = Object.keys(messages)[0]
       typedMessages[0].msgParams.metamaskId = parseInt(msgId)
+      signTypedMsgSpy = sinon.stub(background, 'signTypedMessage')
     })
 
     afterEach(() => {
@@ -786,7 +786,6 @@ describe('Actions', () => {
 
     it('calls signTypedMsg in background with no error', () => {
       const store = mockStore()
-      signTypedMsgSpy = sinon.stub(background, 'signTypedMessage')
 
       store.dispatch(actions.signTypedMsg(msgParamsV3))
       assert(signTypedMsgSpy.calledOnce)
@@ -801,8 +800,6 @@ describe('Actions', () => {
         { type: 'DISPLAY_WARNING', value: 'error' },
       ]
 
-      signTypedMsgSpy = sinon.stub(background, 'signTypedMessage')
-
       signTypedMsgSpy.callsFake((_, callback) => {
         callback(new Error('error'))
       })
diff --git a/ui/app/components/app/account-menu/account-menu.component.js b/ui/app/components/app/account-menu/account-menu.component.js
index 1b81e33a2..7be2bc5dd 100644
--- a/ui/app/components/app/account-menu/account-menu.component.js
+++ b/ui/app/components/app/account-menu/account-menu.component.js
@@ -156,9 +156,11 @@ export default class AccountMenu extends PureComponent {
       case 'Simple Key Pair':
         label = t('imported')
         break
+      default:
+        return null
     }
 
-    return label && (
+    return (
       <div className="keyring-label allcaps">
         { label }
       </div>