diff --git a/app/scripts/controllers/provider-approval.js b/app/scripts/controllers/provider-approval.js
index 3beda6d53..6b5007051 100644
--- a/app/scripts/controllers/provider-approval.js
+++ b/app/scripts/controllers/provider-approval.js
@@ -1,6 +1,7 @@
 const ObservableStore = require('obs-store')
 const SafeEventEmitter = require('safe-event-emitter')
 const createAsyncMiddleware = require('json-rpc-engine/src/createAsyncMiddleware')
+const { errors: rpcErrors } = require('eth-json-rpc-errors')
 
 /**
  * A controller that services user-approved requests for a full Ethereum provider API
@@ -48,7 +49,7 @@ class ProviderApprovalController extends SafeEventEmitter {
       if (approved) {
         res.result = [this.preferencesController.getSelectedAddress()]
       } else {
-        throw new Error('User denied account authorization')
+        throw rpcErrors.eth.userRejectedRequest('User denied account authorization')
       }
     })
   }
diff --git a/app/scripts/controllers/transactions/index.js b/app/scripts/controllers/transactions/index.js
index a33b46851..008d1c72d 100644
--- a/app/scripts/controllers/transactions/index.js
+++ b/app/scripts/controllers/transactions/index.js
@@ -3,6 +3,7 @@ const ObservableStore = require('obs-store')
 const ethUtil = require('ethereumjs-util')
 const Transaction = require('ethereumjs-tx')
 const EthQuery = require('ethjs-query')
+const { errors: rpcErrors } = require('eth-json-rpc-errors')
 const abi = require('human-standard-token-abi')
 const abiDecoder = require('abi-decoder')
 abiDecoder.addABI(abi)
@@ -166,11 +167,11 @@ class TransactionController extends EventEmitter {
           case 'submitted':
             return resolve(finishedTxMeta.hash)
           case 'rejected':
-            return reject(cleanErrorStack(new Error('MetaMask Tx Signature: User denied transaction signature.')))
+            return reject(cleanErrorStack(rpcErrors.eth.userRejectedRequest('MetaMask Tx Signature: User denied transaction signature.')))
           case 'failed':
-            return reject(cleanErrorStack(new Error(finishedTxMeta.err.message)))
+            return reject(cleanErrorStack(rpcErrors.internal(finishedTxMeta.err.message)))
           default:
-            return reject(cleanErrorStack(new Error(`MetaMask Tx Signature: Unknown problem: ${JSON.stringify(finishedTxMeta.txParams)}`)))
+            return reject(cleanErrorStack(rpcErrors.internal(`MetaMask Tx Signature: Unknown problem: ${JSON.stringify(finishedTxMeta.txParams)}`)))
         }
       })
     })
diff --git a/app/scripts/lib/message-manager.js b/app/scripts/lib/message-manager.js
index 898378389..8e1ff34b7 100644
--- a/app/scripts/lib/message-manager.js
+++ b/app/scripts/lib/message-manager.js
@@ -1,6 +1,7 @@
 const EventEmitter = require('events')
 const ObservableStore = require('obs-store')
 const ethUtil = require('ethereumjs-util')
+const { errors: rpcErrors } = require('eth-json-rpc-errors')
 const createId = require('./random-id')
 
 /**
@@ -82,7 +83,7 @@ module.exports = class MessageManager extends EventEmitter {
           case 'signed':
             return resolve(data.rawSig)
           case 'rejected':
-            return reject(new Error('MetaMask Message Signature: User denied message signature.'))
+            return reject(rpcErrors.eth.userRejectedRequest('MetaMask Message Signature: User denied message signature.'))
           default:
             return reject(new Error(`MetaMask Message Signature: Unknown problem: ${JSON.stringify(msgParams)}`))
         }
diff --git a/app/scripts/lib/personal-message-manager.js b/app/scripts/lib/personal-message-manager.js
index d259f4f19..2a2ab481a 100644
--- a/app/scripts/lib/personal-message-manager.js
+++ b/app/scripts/lib/personal-message-manager.js
@@ -1,6 +1,7 @@
 const EventEmitter = require('events')
 const ObservableStore = require('obs-store')
 const ethUtil = require('ethereumjs-util')
+const { errors: rpcErrors } = require('eth-json-rpc-errors')
 const createId = require('./random-id')
 const hexRe = /^[0-9A-Fa-f]+$/g
 const log = require('loglevel')
@@ -88,7 +89,7 @@ module.exports = class PersonalMessageManager extends EventEmitter {
           case 'signed':
             return resolve(data.rawSig)
           case 'rejected':
-            return reject(new Error('MetaMask Message Signature: User denied message signature.'))
+            return reject(rpcErrors.eth.userRejectedRequest('MetaMask Message Signature: User denied message signature.'))
           default:
             return reject(new Error(`MetaMask Message Signature: Unknown problem: ${JSON.stringify(msgParams)}`))
         }
diff --git a/app/scripts/lib/typed-message-manager.js b/app/scripts/lib/typed-message-manager.js
index 5e2a4cd0a..e4d3e842b 100644
--- a/app/scripts/lib/typed-message-manager.js
+++ b/app/scripts/lib/typed-message-manager.js
@@ -2,6 +2,7 @@ const EventEmitter = require('events')
 const ObservableStore = require('obs-store')
 const createId = require('./random-id')
 const assert = require('assert')
+const { errors: rpcErrors } = require('eth-json-rpc-errors')
 const sigUtil = require('eth-sig-util')
 const log = require('loglevel')
 const jsonschema = require('jsonschema')
@@ -78,7 +79,7 @@ module.exports = class TypedMessageManager extends EventEmitter {
           case 'signed':
             return resolve(data.rawSig)
           case 'rejected':
-            return reject(new Error('MetaMask Message Signature: User denied message signature.'))
+            return reject(rpcErrors.eth.userRejectedRequest('MetaMask Message Signature: User denied message signature.'))
           case 'errored':
             return reject(new Error(`MetaMask Message Signature: ${data.error}`))
           default:
diff --git a/package.json b/package.json
index 3cb313af6..11ccfa3c7 100644
--- a/package.json
+++ b/package.json
@@ -85,6 +85,7 @@
     "eth-block-tracker": "^4.4.2",
     "eth-contract-metadata": "^1.9.2",
     "eth-ens-namehash": "^2.0.8",
+    "eth-json-rpc-errors": "^1.1.0",
     "eth-json-rpc-filters": "^4.1.0",
     "eth-json-rpc-infura": "^4.0.1",
     "eth-json-rpc-middleware": "^4.2.0",
@@ -112,7 +113,7 @@
     "gaba": "^1.6.0",
     "human-standard-token-abi": "^2.0.0",
     "jazzicon": "^1.2.0",
-    "json-rpc-engine": "^5.1.3",
+    "json-rpc-engine": "^5.1.4",
     "json-rpc-middleware-stream": "^2.1.1",
     "jsonschema": "^1.2.4",
     "lodash.debounce": "^4.0.8",
diff --git a/yarn.lock b/yarn.lock
index b3d911931..5d33d63b7 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -9776,6 +9776,13 @@ eth-json-rpc-errors@^1.0.1:
   dependencies:
     fast-safe-stringify "^2.0.6"
 
+eth-json-rpc-errors@^1.1.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/eth-json-rpc-errors/-/eth-json-rpc-errors-1.1.0.tgz#2a4291fb20c0483c99b53286a814ed14ca4efb2e"
+  integrity sha512-AAA76BmwwSR5Mws+ivZUYxoDwMygDuMWxSTEmqDXhRPTExSWe5wuJLT/rSfvPSy9+owSudy67JmyRQ02RAOOYQ==
+  dependencies:
+    fast-safe-stringify "^2.0.6"
+
 eth-json-rpc-filters@^4.1.0:
   version "4.1.0"
   resolved "https://registry.yarnpkg.com/eth-json-rpc-filters/-/eth-json-rpc-filters-4.1.0.tgz#e7357a38983cde29858818dc55d394b9cf47c0f0"
@@ -15501,6 +15508,16 @@ json-rpc-engine@^5.1.3:
     promise-to-callback "^1.0.0"
     safe-event-emitter "^1.0.1"
 
+json-rpc-engine@^5.1.4:
+  version "5.1.4"
+  resolved "https://registry.yarnpkg.com/json-rpc-engine/-/json-rpc-engine-5.1.4.tgz#c18d1959eb175049fa7301d4866931ae2f879e47"
+  integrity sha512-nBFWYJ1mvlZL7gqq0M9230SxedL9CbSYO1WgrFi/C1Zo+ZrHUZWLRbr7fUdlLt9TC0G+sf/aEUeuJjR2lHsMvA==
+  dependencies:
+    async "^2.0.1"
+    eth-json-rpc-errors "^1.1.0"
+    promise-to-callback "^1.0.0"
+    safe-event-emitter "^1.0.1"
+
 json-rpc-error@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/json-rpc-error/-/json-rpc-error-2.0.0.tgz#a7af9c202838b5e905c7250e547f1aff77258a02"