diff --git a/MapControl/Shared/MapTileLayer.cs b/MapControl/Shared/MapTileLayer.cs
index 1a851743..1f97e7e5 100644
--- a/MapControl/Shared/MapTileLayer.cs
+++ b/MapControl/Shared/MapTileLayer.cs
@@ -60,7 +60,7 @@ namespace MapControl
 
         public TileMatrix TileMatrix { get; private set; }
 
-        public IReadOnlyCollection<Tile> Tiles { get; private set; } = new List<Tile>();
+        public List<Tile> Tiles { get; private set; } = new List<Tile>();
 
         /// <summary>
         /// Minimum zoom level supported by the MapTileLayer. Default value is 0.
@@ -80,25 +80,32 @@ namespace MapControl
             set { SetValue(MaxZoomLevelProperty, value); }
         }
 
-        protected override void TileSourcePropertyChanged()
+        protected override void UpdateTileLayer(bool tileSourceChanged)
         {
-            if (TileMatrix != null)
-            {
-                Tiles = new List<Tile>();
-                UpdateTiles();
-            }
-        }
+            var update = false;
 
-        protected override void UpdateTileLayer()
-        {
             if (ParentMap == null || !ParentMap.MapProjection.IsWebMercator)
             {
                 TileMatrix = null;
-                UpdateTiles();
+                update = true;
             }
-            else if (SetTileMatrix())
+            else
+            {
+                if (tileSourceChanged)
+                {
+                    Tiles.Clear();
+                    update = true;
+                }
+
+                if (SetTileMatrix())
+                {
+                    SetRenderTransform();
+                    update = true;
+                }
+            }
+
+            if (update)
             {
-                SetRenderTransform();
                 UpdateTiles();
             }
         }
diff --git a/MapControl/Shared/MapTileLayerBase.cs b/MapControl/Shared/MapTileLayerBase.cs
index 8d6bfc05..dd5766ca 100644
--- a/MapControl/Shared/MapTileLayerBase.cs
+++ b/MapControl/Shared/MapTileLayerBase.cs
@@ -26,7 +26,7 @@ namespace MapControl
     {
         public static readonly DependencyProperty TileSourceProperty = DependencyProperty.Register(
             nameof(TileSource), typeof(TileSource), typeof(MapTileLayerBase),
-            new PropertyMetadata(null, (o, e) => ((MapTileLayerBase)o).TileSourcePropertyChanged()));
+            new PropertyMetadata(null, (o, e) => ((MapTileLayerBase)o).Update(true)));
 
         public static readonly DependencyProperty SourceNameProperty = DependencyProperty.Register(
             nameof(SourceName), typeof(string), typeof(MapTileLayerBase), new PropertyMetadata(null));
@@ -59,7 +59,7 @@ namespace MapControl
             TileImageLoader = tileImageLoader;
 
             updateTimer = new DispatcherTimer { Interval = UpdateInterval };
-            updateTimer.Tick += (s, e) => Update();
+            updateTimer.Tick += (s, e) => Update(false);
 
             MapPanel.InitMapElement(this);
         }
@@ -156,7 +156,7 @@ namespace MapControl
                     parentMap.ViewportChanged += OnViewportChanged;
                 }
 
-                Update();
+                Update(false);
             }
         }
 
@@ -164,7 +164,7 @@ namespace MapControl
         {
             if (Children.Count == 0 || e.ProjectionChanged || Math.Abs(e.LongitudeOffset) > 180d)
             {
-                Update(); // update immediately when projection has changed or center has moved across 180° longitude
+                Update(false); // update immediately when projection has changed or center has moved across 180° longitude
             }
             else
             {
@@ -182,17 +182,15 @@ namespace MapControl
             }
         }
 
-        private void Update()
+        private void Update(bool tileSourceChanged)
         {
             updateTimer.Stop();
 
-            UpdateTileLayer();
+            UpdateTileLayer(tileSourceChanged);
         }
 
-        protected abstract void UpdateTileLayer();
+        protected abstract void UpdateTileLayer(bool tileSourceChanged);
 
         protected abstract void SetRenderTransform();
-
-        protected abstract void TileSourcePropertyChanged();
     }
 }
diff --git a/MapControl/Shared/WmtsTileLayer.cs b/MapControl/Shared/WmtsTileLayer.cs
index d7df2c6d..413616d1 100644
--- a/MapControl/Shared/WmtsTileLayer.cs
+++ b/MapControl/Shared/WmtsTileLayer.cs
@@ -83,12 +83,7 @@ namespace MapControl
             return finalSize;
         }
 
-        protected override void TileSourcePropertyChanged()
-        {
-            UpdateTileLayer();
-        }
-
-        protected override void UpdateTileLayer()
+        protected override void UpdateTileLayer(bool tileSourceChanged)
         {
             if (ParentMap == null ||
                 !TileMatrixSets.TryGetValue(ParentMap.MapProjection.CrsId, out WmtsTileMatrixSet tileMatrixSet))