diff --git a/lib/src/Connection.dart b/lib/src/Connection.dart
index 074c3c4..9a9951b 100644
--- a/lib/src/Connection.dart
+++ b/lib/src/Connection.dart
@@ -462,7 +462,7 @@ class Connection {
                 }
               }
 
-              if (userTimestampMap[mxid]["ts"] is int) {
+              if (userTimestampMap[mxid].containsKey("ts")) {
                 if (receiptStateContent[eventID] == null)
                   receiptStateContent[eventID] = {"m.read": {}};
                 else if (receiptStateContent[eventID]["m.read"] == null)
diff --git a/lib/src/RoomList.dart b/lib/src/RoomList.dart
index 5ea3d51..a3ffdeb 100644
--- a/lib/src/RoomList.dart
+++ b/lib/src/RoomList.dart
@@ -180,7 +180,7 @@ class RoomList {
   bool sortLock = false;
 
   sort() {
-    if (sortLock) return;
+    if (sortLock || rooms.length < 2) return;
     sortLock = true;
     rooms?.sort((a, b) =>
         b.timeCreated.toTimeStamp().compareTo(a.timeCreated.toTimeStamp()));
diff --git a/lib/src/Timeline.dart b/lib/src/Timeline.dart
index f64597a..ab0e16c 100644
--- a/lib/src/Timeline.dart
+++ b/lib/src/Timeline.dart
@@ -122,7 +122,7 @@ class Timeline {
   bool sortLock = false;
 
   sort() {
-    if (sortLock) return;
+    if (sortLock || events.length < 2) return;
     sortLock = true;
     events
         ?.sort((a, b) => b.time.toTimeStamp().compareTo(a.time.toTimeStamp()));