diff --git a/.travis.yml b/.travis.yml
index 5102ee5..b6370b2 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,10 +4,10 @@ language: node_js
 
 matrix:
   include:
-  - node_js: 6
-    env: CXX=g++-4.8
   - node_js: 8
     env: CXX=g++-4.8
+  - node_js: 10
+    env: CXX=g++-4.8
     #  - node_js: stable
     #    env: CXX=g++-4.8
 
diff --git a/appveyor.yml b/appveyor.yml
index 046bf91..8ab0d6c 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -3,8 +3,8 @@ version: "{build}"
 
 environment:
   matrix:
-    - nodejs_version: "6"
     - nodejs_version: "8"
+    - nodejs_version: "10"
 
 matrix:
   fast_finish: true
diff --git a/src/index.js b/src/index.js
index ead6c9d..6584d1d 100644
--- a/src/index.js
+++ b/src/index.js
@@ -7,37 +7,25 @@ module.exports = {
   resolver: {
     multicodec: 'raw',
     defaultHashAlg: 'sha2-256',
-    resolve: (binaryBlob, path, callback) => {
-      callback(null, {
+    resolve: async (binaryBlob, path) => {
+      return {
         value: binaryBlob,
         remainderPath: ''
-      })
-    },
-    tree: (binaryBlob, options, callback) => {
-      if (typeof options === 'function') {
-        callback = options
       }
-      callback(null, [])
-    }
+    },
+    tree: async (binaryBlob, options) => []
   },
   util: {
-    deserialize: (data, cb) => {
-      cb(null, data)
-    },
-    serialize: (data, cb) => {
-      cb(null, data)
-    },
-    cid: (data, options, cb) => {
-      if (typeof options === 'function') {
-        cb = options
-        options = {}
-      }
-      options = options || {}
+    deserialize: async (data) => data,
+    serialize: async (data) => data,
+    cid: async (data, options = {}) => {
       const hashAlg = options.hashAlg || 'sha2-256'
       const version = typeof options.version === 'undefined' ? 1 : options.version
-      multihash(data, hashAlg, (err, mh) => {
-        if (err) return cb(err)
-        cb(null, new CID(version, 'raw', mh))
+      return new Promise((resolve, reject) => {
+        multihash(data, hashAlg, (err, mh) => {
+          if (err) return reject(err)
+          resolve(new CID(version, 'raw', mh))
+        })
       })
     }
   }
diff --git a/test/index.spec.js b/test/index.spec.js
index 39be805..6a03bae 100644
--- a/test/index.spec.js
+++ b/test/index.spec.js
@@ -13,12 +13,9 @@ describe('raw codec', () => {
   let testData = Buffer.from('test data')
   let testBlob
 
-  before((done) => {
-    ipldRaw.util.serialize(testData, (err, result) => {
-      expect(err).to.not.exist()
-      testBlob = result
-      done()
-    })
+  before(async () => {
+    const result = await ipldRaw.util.serialize(testData)
+    testBlob = result
   })
 
   it('multicodec is raw', () => {
@@ -29,71 +26,53 @@ describe('raw codec', () => {
     expect(resolver.defaultHashAlg).to.equal('sha2-256')
   })
 
-  it('resolver.resolve', () => {
-    resolver.resolve(testBlob, 'a/b/c/d', (err, result) => {
-      expect(err).to.not.exist()
-      expect(result.value.toString('hex')).to.equal(testData.toString('hex'))
-      expect(result.remainderPath).to.equal('')
-    })
+  it('resolver.resolve', async () => {
+    const result = await resolver.resolve(testBlob, 'a/b/c/d')
+    expect(result.value.toString('hex')).to.equal(testData.toString('hex'))
+    expect(result.remainderPath).to.equal('')
   })
 
-  it('resolver.tree', () => {
-    resolver.tree(testBlob, {}, (err, paths) => {
-      expect(err).to.not.exist()
-      expect(Array.isArray(paths)).to.eql(true)
-      expect(paths.length).to.eql(0)
-    })
+  it('resolver.tree', async () => {
+    const paths = await resolver.tree(testBlob, {})
+    expect(Array.isArray(paths)).to.eql(true)
+    expect(paths.length).to.eql(0)
   })
 
-  it('resolver.tree option parameter can be ignored', () => {
-    resolver.tree(testBlob, (err, paths) => {
-      expect(err).to.not.exist()
-      expect(Array.isArray(paths)).to.eql(true)
-      expect(paths.length).to.eql(0)
-    })
+  it('resolver.tree option parameter can be ignored', async () => {
+    const paths = await resolver.tree(testBlob)
+    expect(Array.isArray(paths)).to.eql(true)
+    expect(paths.length).to.eql(0)
   })
 })
 
 describe('raw util', () => {
   let rawData = Buffer.from('some raw data')
 
-  it('serialize is noop', (done) => {
-    ipldRaw.util.serialize(rawData, (err, result) => {
-      expect(err).to.not.exist()
-      expect(result).to.equal(rawData)
-      done()
-    })
+  it('serialize is noop', async () => {
+    const result = await ipldRaw.util.serialize(rawData)
+    expect(result).to.equal(rawData)
   })
 
-  it('deserialize is noop', (done) => {
-    ipldRaw.util.deserialize(rawData, (err, result) => {
-      expect(err).to.not.exist()
-      expect(result).to.equal(rawData)
-      done()
-    })
+  it('deserialize is noop', async () => {
+    const result = await ipldRaw.util.deserialize(rawData)
+    expect(result).to.equal(rawData)
   })
 
-  it('create cid', (done) => {
-    ipldRaw.util.cid(rawData, (err, cid) => {
-      expect(err).to.not.exist()
-      expect(cid.version).to.equal(1)
-      expect(cid.codec).to.equal('raw')
-      expect(cid.multihash).to.exist()
-      const mh = multihash.decode(cid.multihash)
-      expect(mh.name).to.equal('sha2-256')
-      done()
-    })
+  it('create cid', async () => {
+    const cid = await ipldRaw.util.cid(rawData)
+    expect(cid.version).to.equal(1)
+    expect(cid.codec).to.equal('raw')
+    expect(cid.multihash).to.exist()
+    const mh = multihash.decode(cid.multihash)
+    expect(mh.name).to.equal('sha2-256')
   })
 
-  it('create cid with hashAlg', (done) => {
-    ipldRaw.util.cid(rawData, { hashAlg: 'sha2-512' }, (err, cid) => {
-      expect(err).to.not.exist()
-      expect(cid.version).to.equal(1)
-      expect(cid.codec).to.equal('raw')
-      expect(cid.multihash).to.exist()
-      const mh = multihash.decode(cid.multihash)
-      expect(mh.name).to.equal('sha2-512')
-      done()
-    })
+  it('create cid with hashAlg', async () => {
+    const cid = await ipldRaw.util.cid(rawData, { hashAlg: 'sha2-512' })
+    expect(cid.version).to.equal(1)
+    expect(cid.codec).to.equal('raw')
+    expect(cid.multihash).to.exist()
+    const mh = multihash.decode(cid.multihash)
+    expect(mh.name).to.equal('sha2-512')
   })
 })