diff --git a/test/unit/personal-message-manager-test.js b/test/unit/personal-message-manager-test.js
index 77e1656c5..20481af40 100644
--- a/test/unit/personal-message-manager-test.js
+++ b/test/unit/personal-message-manager-test.js
@@ -91,7 +91,7 @@ describe('Personal Message Manager', function() {
     it('converts text to a utf8 buffer', function() {
       var input = 'hello'
       var output = messageManager.normalizeMsgData(input)
-      assert.equal(output, '0x68656c6c6f', 'predictably hex encoded')
+      assert.equal(output, '0x00680065006c006c006f', 'predictably hex encoded')
     })
 
     it('tolerates a hex prefix', function() {
diff --git a/test/unit/tx-utils-test.js b/test/unit/tx-utils-test.js
new file mode 100644
index 000000000..44d8e13e9
--- /dev/null
+++ b/test/unit/tx-utils-test.js
@@ -0,0 +1,38 @@
+const assert = require('assert')
+const ethUtil = require('ethereumjs-util')
+const BN = ethUtil.BN
+
+const TxUtils = require('../../app/scripts/lib/tx-utils')
+
+
+describe('txUtils', function() {
+  let txUtils
+
+  before(function() {
+    txUtils = new TxUtils()
+  })
+
+  describe('addGasBuffer', function() {
+    describe('adds a flat value', function() {
+      it('over an empty value', function() {
+        const input = '0x0'
+        const output = txUtils.addGasBuffer(input)
+        assert.notEqual(output, input, 'changed the value')
+
+        const inputBn = new BN(input, 'hex')
+        const outputBn = new BN(output, 'hex')
+        assert(outputBn.gt(inputBn), 'returns a greater value')
+      })
+
+      it('over an value', function() {
+        const input = '0x123fad'
+        const output = txUtils.addGasBuffer(input)
+        assert.notEqual(output, input, 'changed the value')
+
+        const inputBn = new BN(input, 'hex')
+        const outputBn = new BN(output, 'hex')
+        assert(outputBn.gt(inputBn), 'returns a greater value')
+      })
+    })
+  })
+})