diff --git a/_locales/en/messages.json b/_locales/en/messages.json
index 9d9b493004..0382d3bd48 100644
--- a/_locales/en/messages.json
+++ b/_locales/en/messages.json
@@ -95,6 +95,16 @@
         }
       }
     },
+    "changedRightAfterVerify": {
+      "message": "Your verification has been cancelled; please review your new safety number with $name$. Remember, this change could mean that someone is trying to intercept your communication or that $name$ has simply reinstalled Signal.",
+      "description": "Shown on the safety number screen when the user has selected to verify/unverify a contact's safety number, and we immediately discover a safety number change",
+      "placeholders": {
+        "name": {
+          "content": "$1",
+          "example": "Bob"
+        }
+      }
+    },
     "changedRecentlyMultiple": {
       "message": "Your safety numbers with multiple group members have changed recently. This could mean that someone is trying to intercept your communication or that they have simply reinstalled Signal.",
       "description": "Shown on confirmation dialog when user attempts to send a message"
diff --git a/background.html b/background.html
index a1129bb755..8f5c07c0c3 100644
--- a/background.html
+++ b/background.html
@@ -169,7 +169,9 @@
     <div class="content">
       <div class='message'>{{ message }}</div>
       <div class='buttons'>
-        <button class='cancel' tabindex='2'>{{ cancel }}</button>
+        {{ #showCancel }}
+          <button class='cancel' tabindex='2'>{{ cancel }}</button>
+        {{ /showCancel }}
         <button class='ok' tabindex='1'>{{ ok }}</button>
       </div>
     </div>
@@ -346,16 +348,16 @@
   </script>
   <script type='text/x-tmpl-mustache' id='key-verification'>
     <div class='container'>
-      {{ ^has_their_key }}
-        <div class='placeholder'>{{ their_key_unknown }}</div>
-      {{ /has_their_key }}
-      {{ #has_their_key }}
+      {{ ^hasTheirKey }}
+        <div class='placeholder'>{{ theirKeyUnknown }}</div>
+      {{ /hasTheirKey }}
+      {{ #hasTheirKey }}
         <label> {{ yourSafetyNumberWith }} </label>
         <!--<div class='qr'></div>-->
         <div class='key'>
           {{ #chunks }} <span>{{ . }}</span> {{ /chunks }}
         </div>
-      {{ /has_their_key }}
+      {{ /hasTheirKey }}
       {{ verifyHelp }}
       <p> {{> link_to_support }} </p>
       <div class='summary'>
diff --git a/js/views/confirmation_dialog_view.js b/js/views/confirmation_dialog_view.js
index b13402f851..17d248f6a6 100644
--- a/js/views/confirmation_dialog_view.js
+++ b/js/views/confirmation_dialog_view.js
@@ -27,6 +27,7 @@
         render_attributes: function() {
             return {
                 message: this.message,
+                showCancel: Boolean(this.reject),
                 cancel: this.cancelText,
                 ok: this.okText
             };
diff --git a/js/views/key_verification_view.js b/js/views/key_verification_view.js
index e5ad2af27f..1ea270b2b2 100644
--- a/js/views/key_verification_view.js
+++ b/js/views/key_verification_view.js
@@ -12,18 +12,20 @@
             'click button.verify': 'toggleVerified',
         },
         initialize: function(options) {
-            this.our_number = textsecure.storage.user.getNumber();
+            this.ourNumber = textsecure.storage.user.getNumber();
             if (options.newKey) {
-              this.their_key = options.newKey;
+              this.theirKey = options.newKey;
             }
 
-            Promise.all([
+            this.loadKeys().then(function() {
+                this.listenTo(this.model, 'change', this.render);
+            }.bind(this));
+        },
+        loadKeys: function() {
+            return Promise.all([
                 this.loadTheirKey(),
                 this.loadOurKey(),
             ]).then(this.generateSecurityNumber.bind(this))
-              .then(function() {
-                this.listenTo(this.model, 'change', this.render);
-              }.bind(this))
               .then(this.render.bind(this));
               //.then(this.makeQRCode.bind(this));
         },
@@ -31,40 +33,59 @@
             // Per Lilia: We can't turn this on until it generates a Latin1 string, as is
             //   required by the mobile clients.
             new QRCode(this.$('.qr')[0]).makeCode(
-                dcodeIO.ByteBuffer.wrap(this.our_key).toString('base64')
+                dcodeIO.ByteBuffer.wrap(this.ourKey).toString('base64')
             );
         },
         loadTheirKey: function() {
-            if (this.their_key) {
-                return Promise.resolve(this.their_key);
-            } else {
-                return textsecure.storage.protocol.loadIdentityKey(
-                    this.model.id
-                ).then(function(their_key) {
-                    this.their_key = their_key;
-                }.bind(this));
-            }
+            return textsecure.storage.protocol.loadIdentityKey(
+                this.model.id
+            ).then(function(theirKey) {
+                this.theirKey = theirKey;
+            }.bind(this));
         },
         loadOurKey: function() {
-            if (this.our_key) {
-                return Promise.resolve(this.our_key);
-            } else {
-                return textsecure.storage.protocol.loadIdentityKey(
-                    this.our_number
-                ).then(function(our_key) {
-                    this.our_key = our_key;
-                }.bind(this));
-            }
+            return textsecure.storage.protocol.loadIdentityKey(
+                this.ourNumber
+            ).then(function(ourKey) {
+                this.ourKey = ourKey;
+            }.bind(this));
         },
         generateSecurityNumber: function() {
             return new libsignal.FingerprintGenerator(5200).createFor(
-                this.our_number, this.our_key, this.model.id, this.their_key
+                this.ourNumber, this.ourKey, this.model.id, this.theirKey
             ).then(function(securityNumber) {
                 this.securityNumber = securityNumber;
             }.bind(this));
         },
+        onSafetyNumberChanged: function() {
+            this.model.getProfiles().then(this.loadKeys.bind(this));
+
+            var dialog = new Whisper.ConfirmationDialogView({
+                message: i18n('changedRightAfterVerify', this.model.getTitle(), this.model.getTitle()),
+                resolve: function() {},
+            });
+
+            dialog.$el.insertBefore(this.el);
+            dialog.focusCancel();
+        },
         toggleVerified: function() {
-            this.model.toggleVerified();
+            this.$('button.verify').attr('disabled', true);
+            this.model.toggleVerified().catch(function(result) {
+                if (result instanceof Error) {
+                    if (result.name === 'OutgoingIdentityKeyError') {
+                        this.onSafetyNumberChanged();
+                    }
+                } else {
+                    var keyError = _.some(result.errors, function(error) {
+                        return error.name === 'OutgoingIdentityKeyError';
+                    });
+                    if (keyError) {
+                        this.onSafetyNumberChanged();
+                    }
+                }
+            }.bind(this)).then(function() {
+                this.$('button.verify').removeAttr('disabled');
+            }.bind(this));
         },
         render_attributes: function() {
             var s = this.securityNumber;
@@ -80,11 +101,11 @@
 
             return {
                 learnMore            : i18n('learnMore'),
-                their_key_unknown    : i18n('theirIdentityUnknown'),
+                theirKeyUnknown      : i18n('theirIdentityUnknown'),
                 yourSafetyNumberWith : i18n('yourSafetyNumberWith', this.model.getTitle()),
                 verifyHelp           : i18n('verifyHelp', this.model.getTitle()),
                 verifyButton         : verifyButton,
-                has_their_key        : this.their_key !== undefined,
+                hasTheirKey          : this.theirKey !== undefined,
                 chunks               : chunks,
                 isVerified           : isVerified,
                 verifiedStatus       : verifiedStatus
diff --git a/test/index.html b/test/index.html
index 2ea61e352e..d5d2bf8085 100644
--- a/test/index.html
+++ b/test/index.html
@@ -173,8 +173,10 @@
     <div class="content">
       <div class='message'>{{ message }}</div>
       <div class='buttons'>
-        <button class='cancel'>{{ cancel }}</button>
-        <button class='ok'>{{ ok }}</button>
+        {{ #showCancel }}
+          <button class='cancel' tabindex='2'>{{ cancel }}</button>
+        {{ /showCancel }}
+        <button class='ok' tabindex='1'>{{ ok }}</button>
       </div>
     </div>
   </script>
@@ -337,16 +339,17 @@
   </script>
   <script type='text/x-tmpl-mustache' id='key-verification'>
     <div class='container'>
-      {{ ^has_their_key }}
-        <div class='placeholder'>{{ their_key_unknown }}</div>
-      {{ /has_their_key }}
-      {{ #has_their_key }}
+      {{ ^hasTheirKey }}
+        <div class='placeholder'>{{ theirKeyUnknown }}</div>
+      {{ /hasTheirKey }}
+      {{ #hasTheirKey }}
         <label> {{ yourSafetyNumberWith }} </label>
         <!--<div class='qr'></div>-->
         <div class='key'>
           {{ #chunks }} <span>{{ . }}</span> {{ /chunks }}
         </div>
-      {{ /has_their_key }}
+      {{ /hasTheirKey }}
+      {{ verifyHelp }}
       <p> {{> link_to_support }} </p>
       <div class='summary'>
         {{ #isVerified }}