diff --git a/app/scripts/lib/id-management.js b/app/scripts/lib/id-management.js
index 30ea866f4..cc50bd649 100644
--- a/app/scripts/lib/id-management.js
+++ b/app/scripts/lib/id-management.js
@@ -69,10 +69,12 @@ function padWithZeroes (number, length) {
 }
 
 function concatSig (v, r, s) {
-  r = padWithZeroes(ethUtil.fromSigned(r), 64)
-  s = padWithZeroes(ethUtil.fromSigned(s), 64)
-  r = ethUtil.stripHexPrefix(r.toString('hex'))
-  s = ethUtil.stripHexPrefix(s.toString('hex'))
-  v = ethUtil.stripHexPrefix(ethUtil.intToHex(v))
-  return ethUtil.addHexPrefix(r.concat(s, v))
+  const rSig = ethUtil.fromSigned(r)
+  const sSig = ethUtil.fromSigned(s)
+  const vSig = ethUtil.bufferToInt(v)
+  const rStr = padWithZeroes(ethUtil.toUnsigned(rSig).toString('hex'), 64)
+  const sStr = padWithZeroes(ethUtil.toUnsigned(sSig).toString('hex'), 64)
+  const vStr = ethUtil.stripHexPrefix(ethUtil.intToHex(vSig))
+  return ethUtil.addHexPrefix(rStr.concat(sStr, vStr)).toString('hex')
 }
+
diff --git a/test/unit/id-management-test.js b/test/unit/id-management-test.js
index 61cdf4d8b..cbc6403bc 100644
--- a/test/unit/id-management-test.js
+++ b/test/unit/id-management-test.js
@@ -16,18 +16,20 @@ describe('IdManagement', function() {
   })
 
   describe('#signMsg', function () {
-    const address = '0x926cD0393816429a580037475ec23eD65fDC893B'
-    const message = '0x96b8d442f4c09a08d266bf37b18219465cfb341c1b3ab9792a6103a93583fdf7'
-    const privateKey = '0xd291f7aa01b94941b446f260bca42c0752762571428ad4ed6239613c66365cf4'
-    const expectedResult = '0x04881196121781472543750166203264808665659193717384627772472141185319786561270240926993050673320157359365329096037150419976876479876332927284781689204045461c'
+    it('passes the dennis test', function() {
+      const address = '0x9858e7d8b79fc3e6d989636721584498926da38a'
+      const message = '0x879a053d4800c6354e76c7985a865d2922c82fb5b3f4577b2fe08b998954f2e0'
+      const privateKey = '0x7dd98753d7b4394095de7d176c58128e2ed6ee600abe97c9f6d9fd65015d9b18'
+      const expectedResult = '0x28fcb6768e5110144a55b2e6ce9d1ea5a58103033632d272d2b5cf506906f7941a00b539383fd872109633d8c71c404e13dba87bc84166ee31b0e36061a69e161c'
 
-    const idManagement = new IdManagement()
-    const exportKeyStub = sinon.stub(idManagement, 'exportPrivateKey', (addr) => {
-      assert.equal(addr, address)
-      return privateKey
+      const idManagement = new IdManagement()
+      const exportKeyStub = sinon.stub(idManagement, 'exportPrivateKey', (addr) => {
+        assert.equal(addr, address)
+        return privateKey
+      })
+
+      const result = idManagement.signMsg(address, message)
+      assert.equal(result, expectedResult)
     })
-
-    const result = idManagement.signMsg(address, message)
-    assert.equal(result, expectedResult)
   })
 })