diff --git a/src/MTXClient.m b/src/MTXClient.m
index ca4da16..4f401d2 100644
--- a/src/MTXClient.m
+++ b/src/MTXClient.m
@@ -423,6 +423,9 @@ validateHomeserver(OFURL *homeserver)
 
 - (void)processRoomsSync: (OFDictionary<OFString *, id> *)rooms
 {
+	[self processJoinedRooms: rooms[@"join"]];
+	[self processInvitedRooms: rooms[@"invite"]];
+	[self processLeftRooms: rooms[@"leave"]];
 }
 
 - (void)processPresenceSync: (OFDictionary<OFString *, id> *)presence
@@ -436,4 +439,30 @@ validateHomeserver(OFURL *homeserver)
 - (void)processToDeviceSync: (OFDictionary<OFString *, id> *)toDevice
 {
 }
+
+- (void)processJoinedRooms: (OFDictionary<OFString *, id> *)rooms
+{
+	if (rooms == nil)
+		return;
+
+	for (OFString *roomID in rooms)
+		[_storage addJoinedRoom: roomID
+				forUser: _userID];
+}
+
+- (void)processInvitedRooms: (OFDictionary<OFString *, id> *)rooms
+{
+	if (rooms == nil)
+		return;
+}
+
+- (void)processLeftRooms: (OFDictionary<OFString *, id> *)rooms
+{
+	if (rooms == nil)
+		return;
+
+	for (OFString *roomID in rooms)
+		[_storage removeJoinedRoom: roomID
+				   forUser: _userID];
+}
 @end
diff --git a/src/MTXSQLite3Storage.m b/src/MTXSQLite3Storage.m
index 81b97c9..1865070 100644
--- a/src/MTXSQLite3Storage.m
+++ b/src/MTXSQLite3Storage.m
@@ -59,7 +59,7 @@
 		    @"SELECT next_batch FROM next_batch\n"
 		    @"WHERE device_id=$device_id"] retain];
 		_joinedRoomsAddStatement = [[_conn prepareStatement:
-		    @"INSERT INTO joined_rooms (\n"
+		    @"INSERT OR REPLACE INTO joined_rooms (\n"
 		    @"    user_id, room_id\n"
 		    @") VALUES (\n"
 		    @"    $user_id, $room_id\n"