diff --git a/src/util.js b/src/util.js
index d536357..eb6850b 100644
--- a/src/util.js
+++ b/src/util.js
@@ -66,10 +66,16 @@ const deserialize = (binaryBlob, callback) => {
  * Get the CID of the DAG-Node.
  *
  * @param {BitcoinBlock} dagNode - Internal representation of a Bitcoin block
+ * @param {Object} [options] - Ignored
  * @param {CidCallback} callback - Callback that handles the return value
  * @returns {void}
  */
-const cid = (dagNode, callback) => {
+const cid = (dagNode, options, callback) => {
+  if (typeof options === 'function') {
+    callback = options
+    options = {}
+  }
+  options = options || {}
   let err = null
   let cid
   try {
diff --git a/test/util.spec.js b/test/util.spec.js
index 6426f59..e2d6194 100644
--- a/test/util.spec.js
+++ b/test/util.spec.js
@@ -150,6 +150,28 @@ describe('IPLD format util API cid()', () => {
       done()
     })
   })
+
+  it('should encode the CID correctly and ignore all options', (done) => {
+    IpldBitcoin.util.deserialize(fixtureBlock, (err, dagNode) => {
+      expect(err).to.not.exist()
+      verifyCid1(
+        dagNode,
+        { hashAlg: 'unknown' },
+        '56203ec2c691d447b2fd0d6a94742345af1f351037dab1ab9e900200000000000000',
+        done)
+    })
+  })
+
+  it('should encode the CID correctly and ignore undefined options', (done) => {
+    IpldBitcoin.util.deserialize(fixtureBlock, (err, dagNode) => {
+      expect(err).to.not.exist()
+      verifyCid1(
+        dagNode,
+        undefined,
+        '56203ec2c691d447b2fd0d6a94742345af1f351037dab1ab9e900200000000000000',
+        done)
+    })
+  })
 })
 
 const verifyBlock = (dagNode, expected) => {
@@ -168,3 +190,11 @@ const verifyCid = (dagNode, expectedCid, doneCb) => {
     doneCb()
   })
 }
+
+const verifyCid1 = (dagNode, options, expectedCid, doneCb) => {
+  IpldBitcoin.util.cid(dagNode, options, (err, cid) => {
+    expect(err).to.not.exist()
+    expect(cid.multihash.toString('hex')).to.equal(expectedCid)
+    doneCb()
+  })
+}