diff --git a/MBTiles/Shared/MBTileSource.cs b/MBTiles/Shared/MBTileSource.cs
index 71539c13..e84b685d 100644
--- a/MBTiles/Shared/MBTileSource.cs
+++ b/MBTiles/Shared/MBTileSource.cs
@@ -30,7 +30,7 @@ namespace MapControl.MBTiles
         {
             Close();
 
-            connection = new SQLiteConnection("Data Source=" + Path.GetFullPath(file));
+            connection = new SQLiteConnection("Data Source=" + Path.GetFullPath(file) + ";Read Only=True");
 
             await connection.OpenAsync();