diff --git a/packages/api-jsonrpc/src/extra/getBlockNumber.js b/packages/api-jsonrpc/src/extra/getBlockNumber.js
deleted file mode 100644
index c941ef0d82..0000000000
--- a/packages/api-jsonrpc/src/extra/getBlockNumber.js
+++ /dev/null
@@ -1,19 +0,0 @@
-// Copyright 2017-2018 Jaco Greeff
-// This software may be modified and distributed under the terms
-// of the ISC license. See the LICENSE file for details.
-// @flow
-
-import type { InterfaceMethodDefinition } from '../types';
-
-/**
-  @name getBlockNumber
-  @signature extra_getBlockNumber (): BlockNumber
-  @summary Retrieves the best blockNumber
-  @description
-    Returns the best blockNumber available on the client
-*/
-module.exports = ({
-  isSubscription: true,
-  inputs: [],
-  output: { type: 'BlockNumber' }
-}: InterfaceMethodDefinition);
diff --git a/packages/api-jsonrpc/src/extra/getClientTime.js b/packages/api-jsonrpc/src/extra/getClientTime.js
deleted file mode 100644
index 0bef7ad2f4..0000000000
--- a/packages/api-jsonrpc/src/extra/getClientTime.js
+++ /dev/null
@@ -1,19 +0,0 @@
-// Copyright 2017-2018 Jaco Greeff
-// This software may be modified and distributed under the terms
-// of the ISC license. See the LICENSE file for details.
-// @flow
-
-import type { InterfaceMethodDefinition } from '../types';
-
-/**
-  @name getClientTime
-  @signature extra_getClientTime (): U64
-  @summary Retrieves the current time
-  @description
-    Returns the current time on the running node
-*/
-module.exports = ({
-  isSubscription: true,
-  inputs: [],
-  output: { type: 'U64' }
-}: InterfaceMethodDefinition);
diff --git a/packages/api-jsonrpc/src/extra/index.js b/packages/api-jsonrpc/src/extra/index.js
deleted file mode 100644
index e7ada3fbda..0000000000
--- a/packages/api-jsonrpc/src/extra/index.js
+++ /dev/null
@@ -1,19 +0,0 @@
-// Copyright 2017-2018 Jaco Greeff
-// This software may be modified and distributed under the terms
-// of the ISC license. See the LICENSE file for details.
-// @flow
-
-import type { InterfaceDefinition } from '../types';
-
-const getBlockNumber = require('./getBlockNumber');
-const getClientTime = require('./getClientTime');
-
-/**
-  @summary Extended methods not available in all clients.
-*/
-module.exports = ({
-  methods: {
-    getBlockNumber,
-    getClientTime
-  }
-}: InterfaceDefinition);
diff --git a/packages/api-jsonrpc/src/index.js b/packages/api-jsonrpc/src/index.js
index ab2b2722d0..a9611a81aa 100644
--- a/packages/api-jsonrpc/src/index.js
+++ b/packages/api-jsonrpc/src/index.js
@@ -7,7 +7,6 @@ import type { InterfaceDefinitions } from './types';
 
 const author = require('./author');
 const chain = require('./chain');
-const extra = require('./extra');
 const state = require('./state');
 
 /**
@@ -16,6 +15,5 @@ const state = require('./state');
 module.exports = ({
   author,
   chain,
-  extra,
   state
 }: InterfaceDefinitions);
diff --git a/packages/api-jsonrpc/src/types.js b/packages/api-jsonrpc/src/types.js
index 9366a36787..6493a5f201 100644
--- a/packages/api-jsonrpc/src/types.js
+++ b/packages/api-jsonrpc/src/types.js
@@ -3,7 +3,7 @@
 // of the ISC license. See the LICENSE file for details.
 // @flow
 
-export type InterfaceTypes = 'author' | 'chain' | 'extra' | 'state';
+export type InterfaceTypes = 'author' | 'chain' | 'state';
 
 export type FormatInputType = 'Bytes' | 'H256' | 'HeaderHash' | 'String';
 
diff --git a/packages/api-provider/src/mock/mocks.js b/packages/api-provider/src/mock/mocks.js
index 0ae3102bfd..8b6bce582f 100644
--- a/packages/api-provider/src/mock/mocks.js
+++ b/packages/api-provider/src/mock/mocks.js
@@ -45,11 +45,6 @@ module.exports = function mocks ({ subscriptions }: MockState): void {
   setInterval(() => {
     newHead = makeBlockHeader(newHead.number);
 
-    updateSubs('extra_getBlockNumber', `0x${(newHead.number).toString(16)}`);
-    updateSubs('chain_newHead', newHead);
+    updateSubs('subscribe_newHead', newHead);
   }, 5000);
-
-  setInterval(() => {
-    updateSubs('extra_getClientTime', `0x${Date.now().toString(16)}`);
-  }, 1000);
 };
diff --git a/packages/api-provider/src/mock/state.js b/packages/api-provider/src/mock/state.js
index 3110ff2ecb..aa58ecf98d 100644
--- a/packages/api-provider/src/mock/state.js
+++ b/packages/api-provider/src/mock/state.js
@@ -13,7 +13,7 @@ const METHODS = Array.prototype.concat.apply(
     return Object
       .keys(interfaces[section].methods)
       .filter((method) => interfaces[section].methods[method].isSubscription)
-      .map((method) => `${section}_${method}`);
+      .map((method) => `subscribe_${method}`);
   })
 );
 
diff --git a/packages/api-provider/src/mock/state.spec.js b/packages/api-provider/src/mock/state.spec.js
index e628639c7b..f3ed44b747 100644
--- a/packages/api-provider/src/mock/state.spec.js
+++ b/packages/api-provider/src/mock/state.spec.js
@@ -24,7 +24,7 @@ describe('state', () => {
     expect(
       state.subscriptions
     ).toMatchObject({
-      'extra_getBlockNumber': {
+      'subscribe_newHead': {
         callbacks: {},
         lastValue: null
       }
diff --git a/packages/api-provider/src/mock/subscribe.spec.js b/packages/api-provider/src/mock/subscribe.spec.js
index c42d2b77c1..5876652521 100644
--- a/packages/api-provider/src/mock/subscribe.spec.js
+++ b/packages/api-provider/src/mock/subscribe.spec.js
@@ -19,7 +19,7 @@ describe('subscribe', () => {
   });
 
   it('returns a subscription id', () => {
-    return subscribe(state, 'extra_getBlockNumber', [() => void 0]).then((id) => {
+    return subscribe(state, 'subscribe_newHead', [() => void 0]).then((id) => {
       expect(id).toEqual(state.subscriptionId);
     });
   });
@@ -27,16 +27,16 @@ describe('subscribe', () => {
   it('stores the mapping values', () => {
     const cb = () => void 0;
 
-    return subscribe(state, 'extra_getBlockNumber', [cb]).then((id) => {
-      expect(state.subscriptionMap[id]).toEqual('extra_getBlockNumber');
-      expect(state.subscriptions['extra_getBlockNumber'].callbacks[id]).toEqual(cb);
+    return subscribe(state, 'subscribe_newHead', [cb]).then((id) => {
+      expect(state.subscriptionMap[id]).toEqual('subscribe_newHead');
+      expect(state.subscriptions['subscribe_newHead'].callbacks[id]).toEqual(cb);
     });
   });
 
   it('calls back with the last known value', (done) => {
-    state.subscriptions['extra_getBlockNumber'].lastValue = 'testValue';
+    state.subscriptions['subscribe_newHead'].lastValue = 'testValue';
 
-    subscribe(state, 'extra_getBlockNumber', [(_, value) => {
+    subscribe(state, 'subscribe_newHead', [(_, value) => {
       expect(value).toEqual('testValue');
       done();
     }]);
diff --git a/packages/api-provider/src/mock/unsubscribe.js b/packages/api-provider/src/mock/unsubscribe.js
index 5ed40caf19..28d24c4b24 100644
--- a/packages/api-provider/src/mock/unsubscribe.js
+++ b/packages/api-provider/src/mock/unsubscribe.js
@@ -5,7 +5,7 @@
 
 import type { MockState } from './types';
 
-module.exports = async function subscribe (self: MockState, _: string, id: number): Promise<boolean> {
+module.exports = async function unsubscribe (self: MockState, _: string, id: number): Promise<boolean> {
   const method = self.subscriptionMap[id];
 
   self.l.debug(() => ['unsubscribe', id, method]);
diff --git a/packages/api-provider/src/mock/unsubscribe.spec.js b/packages/api-provider/src/mock/unsubscribe.spec.js
index 6d3efadd3c..a064d2c9aa 100644
--- a/packages/api-provider/src/mock/unsubscribe.spec.js
+++ b/packages/api-provider/src/mock/unsubscribe.spec.js
@@ -13,23 +13,23 @@ describe('unsubscribe', () => {
   beforeEach(() => {
     state = createState();
 
-    return subscribe(state, 'extra_getBlockNumber', [() => void 0]).then((_id) => {
+    return subscribe(state, 'subscribe_newHead', [() => void 0]).then((_id) => {
       id = _id;
     });
   });
 
   it('fails on unknown ids', () => {
-    return unsubscribe(state, 'extra_getBlockNumber', 5).catch((error) => {
+    return unsubscribe(state, 'subscribe_newHead', 5).catch((error) => {
       expect(error.message).toMatch(/Unable to find/);
     });
   });
 
   it('unsubscribes successfully', () => {
-    return unsubscribe(state, 'extra_getBlockNumber', id);
+    return unsubscribe(state, 'subscribe_newHead', id);
   });
 
   it('fails on double unsubscribe', () => {
-    return unsubscribe(state, 'extra_getBlockNumber', id)
+    return unsubscribe(state, 'subscribe_newHead', id)
       .then(() => unsubscribe(state, id))
       .catch((error) => {
         expect(error.message).toMatch(/Unable to find/);
@@ -37,9 +37,9 @@ describe('unsubscribe', () => {
   });
 
   it('clears the subscriptions', () => {
-    return unsubscribe(state, 'extra_getBlockNumber', id).then(() => {
+    return unsubscribe(state, 'subscribe_newHead', id).then(() => {
       expect(state.subscriptionMap[id]).not.toBeDefined();
-      expect(state.subscriptions['extra_getBlockNumber'].callbacks[id]).not.toBeDefined();
+      expect(state.subscriptions['subscribe_newHead'].callbacks[id]).not.toBeDefined();
     });
   });
 });