diff --git a/src/matrix/room/Room.js b/src/matrix/room/Room.js
index 32434b62..8357bc1d 100644
--- a/src/matrix/room/Room.js
+++ b/src/matrix/room/Room.js
@@ -99,7 +99,7 @@ export class Room extends EventEmitter {
         } else {
             let members;
             if (!this._summary.hasFetchedMembers) {
-                const paginationToken = throw new Error("not implemented");
+                const paginationToken = this._summary.lastPaginationToken;
                 // TODO: move all of this out of Room
                 
                 // if any members are changed by sync while we're fetching members,
diff --git a/src/matrix/room/RoomSummary.js b/src/matrix/room/RoomSummary.js
index 96eba2a8..dd443be3 100644
--- a/src/matrix/room/RoomSummary.js
+++ b/src/matrix/room/RoomSummary.js
@@ -27,7 +27,12 @@ function applySyncResponse(data, roomResponse, membership) {
         data = roomResponse.state.events.reduce(processEvent, data);
     }
     if (roomResponse.timeline) {
-        data = roomResponse.timeline.events.reduce(processEvent, data);
+        const {timeline} = roomResponse;
+        if (timeline.prev_batch) {
+            data = data.cloneIfNeeded();
+            data.lastPaginationToken = timeline.prev_batch;
+        }
+        data = timeline.events.reduce(processEvent, data);
     }
 
     return data;
@@ -99,6 +104,7 @@ class SummaryData {
         this.canonicalAlias = copy ? copy.canonicalAlias : null;
         this.altAliases = copy ? copy.altAliases : null;
         this.hasFetchedMembers = copy ? copy.hasFetchedMembers : false;
+        this.lastPaginationToken = copy ? copy.lastPaginationToken : null;
         this.cloned = copy ? true : false;
     }
 
@@ -153,6 +159,10 @@ export class RoomSummary {
         return this._data.hasFetchedMembers;
     }
 
+    get lastPaginationToken() {
+        return this._data.lastPaginationToken;
+    }
+
     writeHasFetchedMembers(value, txn) {
         const data = new SummaryData(this._data);
         data.hasFetchedMembers = value;