diff --git a/test/unit/reducers/unlock_vault_test.js b/test/unit/reducers/unlock_vault_test.js
new file mode 100644
index 000000000..b7540af08
--- /dev/null
+++ b/test/unit/reducers/unlock_vault_test.js
@@ -0,0 +1,51 @@
+var jsdom = require('mocha-jsdom')
+var assert = require('assert')
+var freeze = require('deep-freeze-strict')
+var path = require('path')
+var sinon = require('sinon')
+
+var actions = require(path.join(__dirname, '..', '..', '..', 'ui', 'app', 'actions.js'))
+var reducers = require(path.join(__dirname, '..', '..',  '..', 'ui', 'app', 'reducers.js'))
+
+describe('#unlockMetamask(selectedAccount)', function() {
+
+  beforeEach(function() {
+    // sinon allows stubbing methods that are easily verified
+    this.sinon = sinon.sandbox.create()
+  })
+
+  afterEach(function() {
+    // sinon requires cleanup otherwise it will overwrite context
+    this.sinon.restore()
+  })
+
+  describe('after an error', function() {
+    it('clears warning', function() {
+      const warning = 'this is the wrong warning'
+      const account = 'foo_account'
+      const initialState = {
+        appState: {
+          warning: warning,
+        }
+      }
+
+      const resultState = reducers(initialState, actions.unlockMetamask(account))
+      assert.equal(resultState.appState.warning, null, 'warning nullified')
+    })
+  })
+
+  describe('going home after an error', function() {
+    it('clears warning', function() {
+      const warning = 'this is the wrong warning'
+      const account = 'foo_account'
+      const initialState = {
+        appState: {
+          warning: warning,
+        }
+      }
+
+      const resultState = reducers(initialState, actions.goHome())
+      assert.equal(resultState.appState.warning, null, 'warning nullified')
+    })
+  })
+})
diff --git a/ui/app/reducers/app.js b/ui/app/reducers/app.js
index a29a8f79c..493246a35 100644
--- a/ui/app/reducers/app.js
+++ b/ui/app/reducers/app.js
@@ -152,6 +152,7 @@ function reduceApp(state, action) {
         privateKey: '',
       },
       transForward: false,
+      warning: null,
     })
 
   case actions.SHOW_ACCOUNT_DETAIL: