diff --git a/CHANGELOG.md b/CHANGELOG.md
index eedfa89c5..4898d27fc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## Current Master
 
+- Fix block gas limit estimation.
+
 ## 3.10.4 2017-9-27
 
 - Fix bug that could mis-render token balances when very small. (Not actually included in 3.9.9)
diff --git a/app/scripts/lib/account-tracker.js b/app/scripts/lib/account-tracker.js
index e2892b1ce..07fc32b10 100644
--- a/app/scripts/lib/account-tracker.js
+++ b/app/scripts/lib/account-tracker.js
@@ -11,6 +11,7 @@ const async = require('async')
 const EthQuery = require('eth-query')
 const ObservableStore = require('obs-store')
 const EventEmitter = require('events').EventEmitter
+const ethUtil = require('ethereumjs-util')
 function noop () {}
 
 
@@ -59,8 +60,9 @@ class AccountTracker extends EventEmitter {
   _updateForBlock (block) {
     const blockNumber = '0x' + block.number.toString('hex')
     this._currentBlockNumber = blockNumber
+    const currentBlockGasLimit = ethUtil.addHexPrefix(block.gasLimit.toString())
 
-    this.store.updateState({ currentBlockGasLimit: `0x${block.gasLimit.toString('hex')}` })
+    this.store.updateState({ currentBlockGasLimit })
 
     async.parallel([
       this._updateAccounts.bind(this),