diff --git a/MBTiles/Shared/MBTileData.cs b/MBTiles/Shared/MBTileData.cs
index 997aea6a..68f3b7b7 100644
--- a/MBTiles/Shared/MBTileData.cs
+++ b/MBTiles/Shared/MBTileData.cs
@@ -16,7 +16,7 @@ using System.Data.SQLite;
 
 namespace MapControl.MBTiles
 {
-    public class MBTileData : IDisposable
+    public sealed class MBTileData : IDisposable
     {
         private readonly SQLiteConnection connection;
 
@@ -37,7 +37,7 @@ namespace MapControl.MBTiles
 
         public void Dispose()
         {
-            Close();
+            connection.Dispose();
         }
 
         public async Task<IDictionary<string, string>> ReadMetadataAsync()
diff --git a/MBTiles/Shared/MBTileSource.cs b/MBTiles/Shared/MBTileSource.cs
index 3a31bcb5..8ebd8795 100644
--- a/MBTiles/Shared/MBTileSource.cs
+++ b/MBTiles/Shared/MBTileSource.cs
@@ -12,7 +12,7 @@ using System.Windows.Media;
 
 namespace MapControl.MBTiles
 {
-    public class MBTileSource : TileSource, IDisposable
+    public sealed class MBTileSource : TileSource, IDisposable
     {
         private readonly MBTileData tileData;