diff --git a/package.json b/package.json
index 04d259c173..7fbc56e0d9 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,8 @@
     "./src/core/runtime/repo-nodejs.js": "./src/core/runtime/repo-browser.js",
     "./src/core/runtime/dns-nodejs.js": "./src/core/runtime/dns-browser.js",
     "./test/utils/create-repo-nodejs.js": "./test/utils/create-repo-browser.js",
-    "stream": "readable-stream"
+    "stream": "readable-stream",
+    "joi": "joi-browser"
   },
   "engines": {
     "node": ">=6.0.0",
@@ -119,6 +120,8 @@
     "is-ipfs": "^0.3.2",
     "is-stream": "^1.1.0",
     "joi": "^13.1.2",
+    "joi-browser": "^13.0.1",
+    "joi-multiaddr": "^1.0.1",
     "libp2p": "~0.18.0",
     "libp2p-circuit": "~0.1.4",
     "libp2p-floodsub": "~0.14.1",
diff --git a/src/core/config.js b/src/core/config.js
new file mode 100644
index 0000000000..493a30e5eb
--- /dev/null
+++ b/src/core/config.js
@@ -0,0 +1,43 @@
+'use strict'
+
+const Joi = require('joi').extend(require('joi-multiaddr'))
+
+const schema = Joi.object().keys({
+  repo: Joi.alternatives().try(
+    Joi.object(), // TODO: schema for IPFS repo
+    Joi.string()
+  ).allow(null),
+  init: Joi.alternatives().try(
+    Joi.boolean(),
+    Joi.object().keys({ bits: Joi.number().integer() })
+  ).allow(null),
+  start: Joi.boolean(),
+  pass: Joi.string().allow(''),
+  EXPERIMENTAL: Joi.object().keys({
+    pubsub: Joi.boolean(),
+    sharding: Joi.boolean(),
+    dht: Joi.boolean()
+  }).allow(null),
+  config: Joi.object().keys({
+    Addresses: Joi.object().keys({
+      Swarm: Joi.array().items(Joi.multiaddr().options({ convert: false })),
+      API: Joi.multiaddr().options({ convert: false }),
+      Gateway: Joi.multiaddr().options({ convert: false })
+    }).allow(null),
+    Discovery: Joi.object().keys({
+      MDNS: Joi.object().keys({
+        Enabled: Joi.boolean(),
+        Interval: Joi.number().integer()
+      }).allow(null),
+      webRTCStar: Joi.object().keys({
+        Enabled: Joi.boolean()
+      }).allow(null)
+    }).allow(null),
+    Bootstrap: Joi.array().items(Joi.multiaddr().IPFS().options({ convert: false }))
+  }).allow(null),
+  libp2p: Joi.object().keys({
+    modules: Joi.object().allow(null) // TODO: schemas for libp2p modules?
+  }).allow(null)
+}).options({ allowUnknown: true })
+
+module.exports.validate = (config) => Joi.attempt(config, schema)
diff --git a/src/core/index.js b/src/core/index.js
index f9912d25d4..d27d178f85 100644
--- a/src/core/index.js
+++ b/src/core/index.js
@@ -12,6 +12,7 @@ const debug = require('debug')
 const extend = require('deep-extend')
 const EventEmitter = require('events')
 
+const config = require('./config')
 const boot = require('./boot')
 const components = require('./components')
 // replaced by repo-browser when running in the browser
@@ -27,7 +28,7 @@ class IPFS extends EventEmitter {
       EXPERIMENTAL: {}
     }
 
-    options = options || {}
+    options = config.validate(options || {})
     this._libp2pModules = options.libp2p && options.libp2p.modules
 
     extend(this._options, options)
diff --git a/test/core/config.spec.js b/test/core/config.spec.js
new file mode 100644
index 0000000000..c90e9454c6
--- /dev/null
+++ b/test/core/config.spec.js
@@ -0,0 +1,220 @@
+/* eslint-env mocha */
+'use strict'
+
+const chai = require('chai')
+const dirtyChai = require('dirty-chai')
+const expect = chai.expect
+chai.use(dirtyChai)
+
+const config = require('../../src/core/config')
+
+describe('config', () => {
+  it('should allow empty config', () => {
+    const cfg = {}
+    expect(() => config.validate(cfg)).to.not.throw()
+  })
+
+  it('should allow undefined config', () => {
+    const cfg = undefined
+    expect(() => config.validate(cfg)).to.not.throw()
+  })
+
+  it('should allow unknown key at root', () => {
+    const cfg = { [`${Date.now()}`]: 'test' }
+    expect(() => config.validate(cfg)).to.not.throw()
+  })
+
+  it('should validate valid repo', () => {
+    const cfgs = [
+      { repo: { unknown: 'value' } },
+      { repo: '/path/to-repo' },
+      { repo: null },
+      { repo: undefined }
+    ]
+
+    cfgs.forEach(cfg => expect(() => config.validate(cfg)).to.not.throw())
+  })
+
+  it('should validate invalid repo', () => {
+    const cfgs = [
+      { repo: 138 }
+    ]
+
+    cfgs.forEach(cfg => expect(() => config.validate(cfg)).to.throw())
+  })
+
+  it('should validate valid init', () => {
+    const cfgs = [
+      { init: { bits: 138 } },
+      { init: { bits: 138, unknown: 'value' } },
+      { init: true },
+      { init: false },
+      { init: null },
+      { init: undefined }
+    ]
+
+    cfgs.forEach(cfg => expect(() => config.validate(cfg)).to.not.throw())
+  })
+
+  it('should validate invalid init', () => {
+    const cfgs = [
+      { init: 138 },
+      { init: { bits: 'not an int' } }
+    ]
+
+    cfgs.forEach(cfg => expect(() => config.validate(cfg)).to.throw())
+  })
+
+  it('should validate valid start', () => {
+    const cfgs = [
+      { start: true },
+      { start: false },
+      { start: undefined }
+    ]
+
+    cfgs.forEach(cfg => expect(() => config.validate(cfg)).to.not.throw())
+  })
+
+  it('should validate invalid start', () => {
+    const cfgs = [
+      { start: 138 },
+      { start: 'make it so number 1' },
+      { start: null }
+    ]
+
+    cfgs.forEach(cfg => expect(() => config.validate(cfg)).to.throw())
+  })
+
+  it('should validate valid pass', () => {
+    const cfgs = [
+      { pass: 'correctbatteryhorsestaple' },
+      { pass: '' },
+      { pass: undefined }
+    ]
+
+    cfgs.forEach(cfg => expect(() => config.validate(cfg)).to.not.throw())
+  })
+
+  it('should validate invalid pass', () => {
+    const cfgs = [
+      { pass: 138 },
+      { pass: null }
+    ]
+
+    cfgs.forEach(cfg => expect(() => config.validate(cfg)).to.throw())
+  })
+
+  it('should validate valid EXPERIMENTAL', () => {
+    const cfgs = [
+      { EXPERIMENTAL: { pubsub: true, dht: true, sharding: true } },
+      { EXPERIMENTAL: { pubsub: false, dht: false, sharding: false } },
+      { EXPERIMENTAL: { unknown: 'value' } },
+      { EXPERIMENTAL: null },
+      { EXPERIMENTAL: undefined }
+    ]
+
+    cfgs.forEach(cfg => expect(() => config.validate(cfg)).to.not.throw())
+  })
+
+  it('should validate invalid EXPERIMENTAL', () => {
+    const cfgs = [
+      { EXPERIMENTAL: { pubsub: 138 } },
+      { EXPERIMENTAL: { dht: 138 } },
+      { EXPERIMENTAL: { sharding: 138 } }
+    ]
+
+    cfgs.forEach(cfg => expect(() => config.validate(cfg)).to.throw())
+  })
+
+  it('should validate valid config', () => {
+    const cfgs = [
+      { config: { Addresses: { Swarm: ['/ip4/0.0.0.0/tcp/4002'] } } },
+      { config: { Addresses: { Swarm: [] } } },
+      { config: { Addresses: { Swarm: undefined } } },
+
+      { config: { Addresses: { API: '/ip4/127.0.0.1/tcp/5002' } } },
+      { config: { Addresses: { API: undefined } } },
+
+      { config: { Addresses: { Gateway: '/ip4/127.0.0.1/tcp/9090' } } },
+      { config: { Addresses: { Gateway: undefined } } },
+
+      { config: { Addresses: { unknown: 'value' } } },
+      { config: { Addresses: null } },
+      { config: { Addresses: undefined } },
+
+      { config: { Discovery: { MDNS: { Enabled: true } } } },
+      { config: { Discovery: { MDNS: { Enabled: false } } } },
+      { config: { Discovery: { MDNS: { Interval: 138 } } } },
+      { config: { Discovery: { MDNS: { unknown: 'value' } } } },
+      { config: { Discovery: { MDNS: null } } },
+      { config: { Discovery: { MDNS: undefined } } },
+
+      { config: { Discovery: { webRTCStar: { Enabled: true } } } },
+      { config: { Discovery: { webRTCStar: { Enabled: false } } } },
+      { config: { Discovery: { webRTCStar: { unknown: 'value' } } } },
+      { config: { Discovery: { webRTCStar: null } } },
+      { config: { Discovery: { webRTCStar: undefined } } },
+
+      { config: { Discovery: { unknown: 'value' } } },
+      { config: { Discovery: null } },
+      { config: { Discovery: undefined } },
+
+      { config: { Bootstrap: ['/ip4/104.236.176.52/tcp/4001/ipfs/QmSoLnSGccFuZQJzRadHn95W2CrSFmZuTdDWP8HXaHca9z'] } },
+      { config: { Bootstrap: [] } },
+
+      { config: { unknown: 'value' } },
+      { config: null },
+      { config: undefined }
+    ]
+
+    cfgs.forEach(cfg => expect(() => config.validate(cfg)).to.not.throw())
+  })
+
+  it('should validate invalid config', () => {
+    const cfgs = [
+      { config: { Addresses: { Swarm: 138 } } },
+      { config: { Addresses: { Swarm: null } } },
+
+      { config: { Addresses: { API: 138 } } },
+      { config: { Addresses: { API: null } } },
+
+      { config: { Addresses: { Gateway: 138 } } },
+      { config: { Addresses: { Gateway: null } } },
+
+      { config: { Discovery: { MDNS: { Enabled: 138 } } } },
+      { config: { Discovery: { MDNS: { Interval: true } } } },
+
+      { config: { Discovery: { webRTCStar: { Enabled: 138 } } } },
+
+      { config: { Bootstrap: ['/ip4/0.0.0.0/tcp/4002'] } },
+      { config: { Bootstrap: 138 } },
+
+      { config: 138 }
+    ]
+
+    cfgs.forEach(cfg => expect(() => config.validate(cfg)).to.throw())
+  })
+
+  it('should validate valid libp2p', () => {
+    const cfgs = [
+      { libp2p: { modules: {} } },
+      { libp2p: { modules: { unknown: 'value' } } },
+      { libp2p: { modules: null } },
+      { libp2p: { modules: undefined } },
+      { libp2p: { unknown: 'value' } },
+      { libp2p: null },
+      { libp2p: undefined }
+    ]
+
+    cfgs.forEach(cfg => expect(() => config.validate(cfg)).to.not.throw())
+  })
+
+  it('should validate invalid libp2p', () => {
+    const cfgs = [
+      { libp2p: { modules: 138 } },
+      { libp2p: 138 }
+    ]
+
+    cfgs.forEach(cfg => expect(() => config.validate(cfg)).to.throw())
+  })
+})