diff --git a/src/ScalarMessaging.js b/src/ScalarMessaging.js
index 3325044b84..fa7b8c5b76 100644
--- a/src/ScalarMessaging.js
+++ b/src/ScalarMessaging.js
@@ -480,7 +480,7 @@ function getMembershipCount(event, roomId) {
         sendError(event, _t('This room is not recognised.'));
         return;
     }
-    const count = room.getJoinedMembers().length;
+    const count = room.getJoinedMemberCount();
     sendResponse(event, count);
 }
 
@@ -497,12 +497,11 @@ function canSendEvent(event, roomId) {
         sendError(event, _t('This room is not recognised.'));
         return;
     }
-    const me = client.credentials.userId;
-    const member = room.getMember(me);
-    if (!member || member.membership !== "join") {
+    if (room.getMyMembership() !== "join") {
         sendError(event, _t('You are not in this room.'));
         return;
     }
+    const me = client.credentials.userId;
 
     let canSend = false;
     if (isState) {
diff --git a/src/VectorConferenceHandler.js b/src/VectorConferenceHandler.js
index 9ba46b2ab6..c53a01d464 100644
--- a/src/VectorConferenceHandler.js
+++ b/src/VectorConferenceHandler.js
@@ -72,7 +72,7 @@ ConferenceCall.prototype._getConferenceUserRoom = function() {
     for (var i = 0; i < rooms.length; i++) {
         var confUser = rooms[i].getMember(this.confUserId);
         if (confUser && confUser.membership === "join" &&
-                rooms[i].getJoinedMembers().length === 2) {
+                rooms[i].getJoinedMemberCount() === 2) {
             confRoom = rooms[i];
             break;
         }
diff --git a/src/components/structures/RightPanel.js b/src/components/structures/RightPanel.js
index 18523ceb59..bd4ed722cb 100644
--- a/src/components/structures/RightPanel.js
+++ b/src/components/structures/RightPanel.js
@@ -280,7 +280,7 @@ module.exports = React.createClass({
             const room = cli.getRoom(this.props.roomId);
             let isUserInRoom;
             if (room) {
-                const numMembers = room.getJoinedMembers().length;
+                const numMembers = room.getJoinedMemberCount();
                 membersTitle = _t('%(count)s Members', { count: numMembers });
                 membersBadge = <div title={membersTitle}>{ formatCount(numMembers) }</div>;
                 isUserInRoom = room.hasMembershipState(this.context.matrixClient.credentials.userId, 'join');
diff --git a/src/components/structures/RoomView.js b/src/components/structures/RoomView.js
index 855090873f..7b7a7bb813 100644
--- a/src/components/structures/RoomView.js
+++ b/src/components/structures/RoomView.js
@@ -310,7 +310,7 @@ module.exports = React.createClass({
                 });
             } else if (room) {
                 //viewing a previously joined room, try to lazy load members
-                
+
                 // Stop peeking because we have joined this room previously
                 MatrixClientPeg.get().stopPeeking();
                 this.setState({isPeeking: false});
@@ -363,7 +363,7 @@ module.exports = React.createClass({
         // XXX: EVIL HACK to autofocus inviting on empty rooms.
         // We use the setTimeout to avoid racing with focus_composer.
         if (this.state.room &&
-            this.state.room.getJoinedMembers().length == 1 &&
+            this.state.room.getJoinedMemberCount() == 1 &&
             this.state.room.getLiveTimeline() &&
             this.state.room.getLiveTimeline().getEvents() &&
             this.state.room.getLiveTimeline().getEvents().length <= 6) {
@@ -1507,9 +1507,8 @@ module.exports = React.createClass({
             }
         }
 
-        const myUserId = MatrixClientPeg.get().credentials.userId;
-        const myMember = this.state.room.getMember(myUserId);
-        if (myMember && myMember.membership == 'invite') {
+        const myMembership = this.state.room.getMyMembership();
+        if (myMembership == 'invite') {
             if (this.state.joining || this.state.rejecting) {
                 return (
                     <div className="mx_RoomView">
@@ -1517,6 +1516,8 @@ module.exports = React.createClass({
                     </div>
                 );
             } else {
+                const myUserId = MatrixClientPeg.get().credentials.userId;
+                const myMember = this.state.room.getMember(myUserId);
                 const inviteEvent = myMember.events.member;
                 var inviterName = inviteEvent.sender ? inviteEvent.sender.name : inviteEvent.getSender();
 
@@ -1600,7 +1601,7 @@ module.exports = React.createClass({
         } else if (this.state.showingPinned) {
             hideCancel = true; // has own cancel
             aux = <PinnedEventsPanel room={this.state.room} onCancelClick={this.onPinnedClick} />;
-        } else if (!myMember || myMember.membership !== "join") {
+        } else if (myMembership !== "join") {
             // We do have a room object for this room, but we're not currently in it.
             // We may have a 3rd party invite to it.
             var inviterName = undefined;
@@ -1642,7 +1643,7 @@ module.exports = React.createClass({
         let messageComposer, searchInfo;
         const canSpeak = (
             // joined and not showing search results
-            myMember && (myMember.membership == 'join') && !this.state.searchResults
+            myMembership == 'join' && !this.state.searchResults
         );
         if (canSpeak) {
             messageComposer =
@@ -1777,15 +1778,15 @@ module.exports = React.createClass({
                     oobData={this.props.oobData}
                     editing={this.state.editingRoomSettings}
                     saving={this.state.uploadingRoomSettings}
-                    inRoom={myMember && myMember.membership === 'join'}
+                    inRoom={myMembership === 'join'}
                     collapsedRhs={this.props.collapsedRhs}
                     onSearchClick={this.onSearchClick}
                     onSettingsClick={this.onSettingsClick}
                     onPinnedClick={this.onPinnedClick}
                     onSaveClick={this.onSettingsSaveClick}
                     onCancelClick={(aux && !hideCancel) ? this.onCancelClick : null}
-                    onForgetClick={(myMember && myMember.membership === "leave") ? this.onForgetClick : null}
-                    onLeaveClick={(myMember && myMember.membership === "join") ? this.onLeaveClick : null}
+                    onForgetClick={(myMembership === "leave") ? this.onForgetClick : null}
+                    onLeaveClick={(myMembership === "join") ? this.onLeaveClick : null}
                 />
                 { auxPanel }
                 <div className={fadableSectionClasses}>
diff --git a/src/components/views/context_menus/RoomTileContextMenu.js b/src/components/views/context_menus/RoomTileContextMenu.js
index 77f71fa8fa..ce9895447e 100644
--- a/src/components/views/context_menus/RoomTileContextMenu.js
+++ b/src/components/views/context_menus/RoomTileContextMenu.js
@@ -346,20 +346,18 @@ module.exports = React.createClass({
     },
 
     render: function() {
-        const myMember = this.props.room.getMember(
-            MatrixClientPeg.get().credentials.userId,
-        );
+        const myMembership = this.props.room.getMyMembership();
 
         // Can't set notif level or tags on non-join rooms
-        if (myMember.membership !== 'join') {
-            return this._renderLeaveMenu(myMember.membership);
+        if (myMembership !== 'join') {
+            return this._renderLeaveMenu(myMembership);
         }
 
         return (
             <div>
                 { this._renderNotifMenu() }
                 <hr className="mx_RoomTileContextMenu_separator" />
-                { this._renderLeaveMenu(myMember.membership) }
+                { this._renderLeaveMenu(myMembership) }
                 <hr className="mx_RoomTileContextMenu_separator" />
                 { this._renderRoomTagMenu() }
             </div>
diff --git a/src/components/views/rooms/RoomSettings.js b/src/components/views/rooms/RoomSettings.js
index 7a78d205b9..3b95fa9905 100644
--- a/src/components/views/rooms/RoomSettings.js
+++ b/src/components/views/rooms/RoomSettings.js
@@ -794,15 +794,15 @@ module.exports = React.createClass({
         }
 
         let leaveButton = null;
-        const myMember = this.props.room.getMember(myUserId);
-        if (myMember) {
-            if (myMember.membership === "join") {
+        const myMemberShip = this.props.room.getMyMembership();
+        if (myMemberShip) {
+            if (myMemberShip === "join") {
                 leaveButton = (
                     <AccessibleButton className="mx_RoomSettings_leaveButton" onClick={this.onLeaveClick}>
                         { _t('Leave room') }
                     </AccessibleButton>
                 );
-            } else if (myMember.membership === "leave") {
+            } else if (myMemberShip === "leave") {
                 leaveButton = (
                     <AccessibleButton className="mx_RoomSettings_leaveButton" onClick={this.onForgetClick}>
                         { _t('Forget room') }
diff --git a/test/test-utils.js b/test/test-utils.js
index 975a4df0ee..25df9686ff 100644
--- a/test/test-utils.js
+++ b/test/test-utils.js
@@ -256,6 +256,7 @@ export function mkStubRoom(roomId = null) {
         getAccountData: () => null,
         hasMembershipState: () => null,
         getVersion: () => '1',
+        getMyMembership: () => "join",
         currentState: {
             getStateEvents: sinon.stub(),
             mayClientSendStateEvent: sinon.stub().returns(true),