diff --git a/src/models/room-state.js b/src/models/room-state.js
index 2ed858ab8..69fe27abc 100644
--- a/src/models/room-state.js
+++ b/src/models/room-state.js
@@ -79,6 +79,8 @@ function RoomState(roomId, oobMemberFlags = undefined) {
     this._userIdsToDisplayNames = {};
     this._tokenToInvite = {}; // 3pid invite state_key to m.room.member invite
     this._joinedMemberCount = null; // cache of the number of joined members
+    this._invitedMemberCount = null;
+
     if (!oobMemberFlags) {
         oobMemberFlags = {
             status: OOB_STATUS_NOTSTARTED,
@@ -102,9 +104,33 @@ RoomState.prototype.getJoinedMemberCount = function() {
     return this._joinedMemberCount;
 };
 
+/**
+ * Set the joined member count explicitly (like from summary part of the sync response)
+ * @param {number} count the amount of joined members
+ */
 RoomState.prototype.setJoinedMemberCount = function(count) {
     this._joinedMemberCount = count;
 }
+/**
+ * Returns the number of invited members in this room
+ * @return {integer} The number of members in this room whose membership is 'invite'
+ */
+RoomState.prototype.getInvitedMemberCount = function() {
+    if (this._invitedMemberCount === null) {
+        this._invitedMemberCount = this.getMembers().filter((m) => {
+            return m.membership === 'invite';
+        }).length;
+    }
+    return this._invitedMemberCount;
+};
+
+/**
+ * Set the amount of invited members in this room
+ * @param {number} count the amount of invited members
+ */
+RoomState.prototype.setInvitedMemberCount = function(count) {
+    this._invitedMemberCount = count;
+}
 
 /**
  * Get all RoomMembers in this room.
@@ -193,6 +219,9 @@ RoomState.prototype.clone = function() {
     // Ugly hack: see above
     this._oobMemberFlags.status = status;
 
+    copy.setJoinedMemberCount(this.getJoinedMemberCount());
+    copy.setInvitedMemberCount(this.getInvitedMemberCount());
+
     // copy out of band flags if needed
     if (this._oobMemberFlags.status == OOB_STATUS_FINISHED) {
         // copy markOutOfBand flags
diff --git a/src/models/room.js b/src/models/room.js
index fd4627768..ff5dcb1f3 100644
--- a/src/models/room.js
+++ b/src/models/room.js
@@ -379,12 +379,18 @@ Room.prototype.setUnreadNotificationCount = function(type, count) {
 };
 
 Room.prototype.setSummary = function(summary) {
-    const heros = summary["m.heroes"];
-    const count = summary["m.joined_member_count"];
-    if (Number.isInteger(count)) {
-        this.currentState.setJoinedMemberCount(count);
+    const heroes = summary["m.heroes"];
+    const joinedCount = summary["m.joined_member_count"];
+    const invitedCount = summary["m.invited_member_count"];
+    if (Number.isInteger(joinedCount)) {
+        this.currentState.setJoinedMemberCount(joinedCount);
+    }
+    if (Number.isInteger(invitedCount)) {
+        this.currentState.setInvitedMemberCount(invitedCount);
+    }
+    if (heroes) {
+        this._summaryHeroes = heroes;
     }
-    this._summaryHeroes = heros;
 }
 
 /**
diff --git a/src/sync-accumulator.js b/src/sync-accumulator.js
index 3ff71af77..1a617d0ab 100644
--- a/src/sync-accumulator.js
+++ b/src/sync-accumulator.js
@@ -63,7 +63,11 @@ class SyncAccumulator {
             //       { event: $event, token: null|token },
             //       ...
             //    ],
-            //    _summary: { m.heroes: [ $user_id ], m.joined_member_count: $count }
+            //    _summary: {
+            //       m.heroes: [ $user_id ],
+            //       m.joined_member_count: $count,
+            //       m.invited_member_count: $count
+            //    },
             //    _accountData: { $event_type: json },
             //    _unreadNotifications: { ... unread_notifications JSON ... },
             //    _readReceipts: { $user_id: { data: $json, eventId: $event_id }}
@@ -261,7 +265,15 @@ class SyncAccumulator {
             currentData._unreadNotifications = data.unread_notifications;
         }
         if (data.summary) {
-            currentData._summary = data.summary;
+            const HEROES_KEY = "m.heroes";
+            const INVITED_COUNT_KEY = "m.invited_member_count";
+            const JOINED_COUNT_KEY = "m.joined_member_count";
+            
+            const acc = currentData._summary;
+            const sum = data.summary;
+            acc[HEROES_KEY] = sum[HEROES_KEY] || acc[HEROES_KEY];
+            acc[JOINED_COUNT_KEY] = sum[JOINED_COUNT_KEY] || acc[JOINED_COUNT_KEY];
+            acc[INVITED_COUNT_KEY] = sum[INVITED_COUNT_KEY] || acc[INVITED_COUNT_KEY];
         }
 
         if (data.ephemeral && data.ephemeral.events) {
diff --git a/src/sync.js b/src/sync.js
index c3c8970e8..c912d62d0 100644
--- a/src/sync.js
+++ b/src/sync.js
@@ -823,7 +823,11 @@ SyncApi.prototype._processSyncResponse = async function(
     //          state: { events: [] },
     //          timeline: { events: [], prev_batch: $token, limited: true },
     //          ephemeral: { events: [] },
-    //          summary: { m.heroes: [ $userId ], m.joined_member_count: $count }
+    //          summary: {
+    //             m.heroes: [ $user_id ],
+    //             m.joined_member_count: $count,
+    //             m.invited_member_count: $count
+    //          },
     //          account_data: { events: [] },
     //          unread_notifications: {
     //              highlight_count: 0,