diff --git a/FileDbCache/UWP/FileDbCache.cs b/FileDbCache/UWP/FileDbCache.cs
index dcd73c06..34eb4be9 100644
--- a/FileDbCache/UWP/FileDbCache.cs
+++ b/FileDbCache/UWP/FileDbCache.cs
@@ -2,6 +2,7 @@
 // © 2019 Clemens Fischer
 // Licensed under the Microsoft Public License (Ms-PL)
 
+using FileDbNs;
 using System;
 using System.Diagnostics;
 using System.IO;
@@ -10,7 +11,6 @@ using System.Threading.Tasks;
 using Windows.Storage;
 using Windows.Storage.Streams;
 using Windows.UI.Xaml;
-using FileDbNs;
 
 namespace MapControl.Caching
 {
diff --git a/MapControl/UWP/ImageFileCache.UWP.cs b/MapControl/UWP/ImageFileCache.UWP.cs
index 8c0561d8..090a162b 100644
--- a/MapControl/UWP/ImageFileCache.UWP.cs
+++ b/MapControl/UWP/ImageFileCache.UWP.cs
@@ -27,7 +27,7 @@ namespace MapControl.Caching
             Debug.WriteLine("Created ImageFileCache in " + rootFolder.Path);
         }
 
-        public virtual async Task<ImageCacheItem> GetAsync(string key)
+        public async Task<ImageCacheItem> GetAsync(string key)
         {
             string path = null;
 
@@ -67,7 +67,7 @@ namespace MapControl.Caching
             return null;
         }
 
-        public virtual async Task SetAsync(string key, IBuffer buffer, DateTime expiration)
+        public async Task SetAsync(string key, IBuffer buffer, DateTime expiration)
         {
             var paths = key.Split('\\', '/', ',', ':', ';');