diff --git a/libaxolotl/protocol.js b/libaxolotl/protocol.js
index e0f3617b..e63f5403 100644
--- a/libaxolotl/protocol.js
+++ b/libaxolotl/protocol.js
@@ -113,6 +113,16 @@ window.axolotl.protocol = function() {
                 openSessionRemaining = true;
         if (!openSessionRemaining) // Used as a flag to get new pre keys for the next session
             record.registrationId = null;
+        else if (record.registrationId === null && registrationId !== undefined)
+            record.registrationId = registrationId;
+        else if (record.registrationId === null)
+            throw new Error("Had open sessions on a record that had no registrationId set");
+
+        var identityKey = axolotl.api.storage.identityKeys.get(encodedNumber);
+        if (identityKey === undefined)
+            axolotl.api.storage.identityKeys.put(encodedNumber, record.identityKey);
+        else if (getString(identityKey) !== getString(record.identityKey))
+            throw new Error("Tried to change identity key at save time");
 
         axolotl.api.storage.sessions.put(encodedNumber, record);
     }
@@ -160,8 +170,12 @@ window.axolotl.protocol = function() {
 
     crypto_storage.getSessionOrIdentityKeyByBaseKey = function(encodedNumber, baseKey) {
         var record = axolotl.api.storage.sessions.get(encodedNumber);
-        if (record === undefined)
-            return undefined;
+        if (record === undefined) {
+            var identityKey = axolotl.api.storage.identityKeys.get(encodedNumber);
+            if (identityKey === undefined)
+                return undefined;
+            return { indexInfo: { remoteIdentityKey: identityKey } };
+        }
         var sessions = record._sessions;
 
         var preferredSession = record._sessions[getString(baseKey)];
diff --git a/libaxolotl/test/fake_api.js b/libaxolotl/test/fake_api.js
index 722a33ab..dfbd3c8f 100644
--- a/libaxolotl/test/fake_api.js
+++ b/libaxolotl/test/fake_api.js
@@ -1,6 +1,7 @@
 'use strict';
 
 var testSessionMap = {};
+var testIdentityKeysMap = {};
 
 ;(function() {
     window.axolotl = window.axolotl || {};
@@ -24,6 +25,15 @@ var testSessionMap = {};
                 localStorage.removeItem(key);
             },
 
+            identityKeys: {
+                get: function(identifier) {
+                    return testIdentityKeysMap[identifier];
+                },
+                put: function(identifier, identityKey) {
+                    testIdentityKeysMap[identifier] = identityKey;
+                },
+            },
+
             sessions: {
                 get: function(identifier) {
                     return testSessionMap[identifier];
diff --git a/libaxolotl/test/protocol_test.js b/libaxolotl/test/protocol_test.js
index a554eaf5..4f53ab46 100644
--- a/libaxolotl/test/protocol_test.js
+++ b/libaxolotl/test/protocol_test.js
@@ -224,6 +224,7 @@ describe('Protocol', function() {
                 it(axolotlTestVectors[i].name, function(done) {
                     localStorage.clear();
                     testSessionMap = {};
+                    testIdentityKeysMap = {};
                     return runAxolotlTest(axolotlTestVectors[i].vectors).then(function(res) {
                         assert(res);
                     }).then(done).catch(done);
diff --git a/libtextsecure/axolotl_wrapper.js b/libtextsecure/axolotl_wrapper.js
index f6c6e0e3..3c404891 100644
--- a/libtextsecure/axolotl_wrapper.js
+++ b/libtextsecure/axolotl_wrapper.js
@@ -19,17 +19,22 @@
                 return textsecure.storage.removeEncrypted(key);
             },
 
+            identityKeys: {
+                get: function(identifier) {
+                    return textsecure.storage.devices.getIdentityKeyForNumber(textsecure.utils.unencodeNumber(identifier)[0]);
+                },
+                put: function(identifier, identityKey) {
+                    return textsecure.storage.devices.checkSaveIdentityKeyForNumber(textsecure.utils.unencodeNumber(identifier)[0], identityKey);
+                },
+            },
+
             sessions: {
                 get: function(identifier) {
                     var device = textsecure.storage.devices.getDeviceObject(identifier, true);
-                    if (device === undefined)
+                    if (device === undefined || device.sessions === undefined)
                         return undefined;
                     var record = new axolotl.sessions.RecipientRecord();
-                    if (device.sessions !== undefined)
-                        record.deserialize(device.sessions);
-                    else
-                        // TODO: (even for numbers, not devices) We MUST return an identityKey if we have one available
-                        record.identityKey = device.identityKey;
+                    record.deserialize(device.sessions);
                     if (getString(device.identityKey) !== getString(record.identityKey))
                         throw new Error("Got mismatched identity key on sessions load");
                     return record;
diff --git a/libtextsecure/storage/devices.js b/libtextsecure/storage/devices.js
index 382332a7..e21d2f36 100644
--- a/libtextsecure/storage/devices.js
+++ b/libtextsecure/storage/devices.js
@@ -49,6 +49,19 @@
             return map === undefined ? [] : map.devices;
         },
 
+        getIdentityKeyForNumber: function(number) {
+            var map = textsecure.storage.getEncrypted("devices" + number);
+            return map === undefined ? undefined : map.identityKey;
+        },
+
+        checkSaveIdentityKeyForNumber: function(number, identityKey) {
+            var map = textsecure.storage.getEncrypted("devices" + number);
+            if (map === undefined)
+                textsecure.storage.putEncrypted("devices" + number, { devices: [], identityKey: identityKey});
+            else if (getString(map.identityKey) !== getString(identityKey))
+                throw new Error("Attempted to overwrite a different identity key");
+        },
+
         getDeviceObject: function(encodedNumber, returnIdentityKey) {
             var number = textsecure.utils.unencodeNumber(encodedNumber)[0];
             var devices = textsecure.storage.devices.getDeviceObjectsForNumber(number);