diff --git a/package.json b/package.json
index bfdc489..f7c3ea4 100644
--- a/package.json
+++ b/package.json
@@ -34,15 +34,16 @@
   },
   "homepage": "https://github.com/libp2p/js-peer-id",
   "devDependencies": {
-    "aegir": "^11.0.0",
+    "aegir": "^11.0.1",
     "chai": "^3.5.0",
     "dirty-chai": "^1.2.2",
     "pre-commit": "^1.2.2"
   },
   "dependencies": {
-    "libp2p-crypto": "~0.8.6",
-    "multihashes": "~0.4.4",
-    "async": "^2.1.5"
+    "async": "^2.2.0",
+    "libp2p-crypto": "~0.8.7",
+    "lodash": "^4.17.4",
+    "multihashes": "~0.4.5"
   },
   "repository": {
     "type": "git",
@@ -59,4 +60,4 @@
     "nginnever <ginneversource@gmail.com>",
     "npmcdn-to-unpkg-bot <npmcdn-to-unpkg-bot@users.noreply.github.com>"
   ]
-}
\ No newline at end of file
+}
diff --git a/src/index.js b/src/index.js
index 9cf6fb0..c1baba8 100644
--- a/src/index.js
+++ b/src/index.js
@@ -91,7 +91,6 @@ class PeerId {
 }
 
 exports = module.exports = PeerId
-exports.Buffer = Buffer
 
 // generation
 exports.create = function (opts, callback) {
@@ -219,6 +218,12 @@ exports.createFromJSON = function (obj, callback) {
   }
 }
 
+exports.isPeerId = function (peerId) {
+  return Boolean(typeof peerId === 'object' &&
+    peerId._id &&
+    peerId._idB58String)
+}
+
 function toB64Opt (val) {
   if (val) {
     return val.toString('base64')
diff --git a/test/index.spec.js b/test/index.spec.js
index 782747c..5cbc952 100644
--- a/test/index.spec.js
+++ b/test/index.spec.js
@@ -32,6 +32,16 @@ describe('PeerId', () => {
     })
   })
 
+  it('isPeerId', (done) => {
+    PeerId.create((err, id) => {
+      expect(err).to.not.exist()
+      expect(PeerId.isPeerId(id)).to.equal(true)
+      expect(PeerId.isPeerId('aaa')).to.equal(false)
+      expect(PeerId.isPeerId(new Buffer('batatas'))).to.equal(false)
+      done()
+    })
+  })
+
   it('throws on changing the id', (done) => {
     PeerId.create((err, id) => {
       expect(err).to.not.exist()