diff --git a/CHANGELOG.md b/CHANGELOG.md
index 479e422f2..20651dbad 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## Current Master
 
+- Fix overly strict validation where transactions were rejected with hex encoded "chainId"
+
 ## 4.5.1 Tue Apr 03 2018
 
 - Fix default network (should be mainnet not Rinkeby)
diff --git a/app/scripts/lib/tx-state-manager.js b/app/scripts/lib/tx-state-manager.js
index 9e597ef37..2ab24d6a0 100644
--- a/app/scripts/lib/tx-state-manager.js
+++ b/app/scripts/lib/tx-state-manager.js
@@ -143,7 +143,7 @@ module.exports = class TransactionStateManager extends EventEmitter {
       // validate types
       switch (key) {
         case 'chainId':
-          if (typeof value !== 'number') throw new Error(`${key} in txParams is not a Number. got: (${value})`)
+          if (typeof value !== 'number' && typeof value !== 'string') throw new Error(`${key} in txParams is not a Number or hex string. got: (${value})`)
           break
         default:
           if (typeof value !== 'string') throw new Error(`${key} in txParams is not a string. got: (${value})`)