diff --git a/jQuery-File-Upload.MVC3/Upload/FilesStatus.cs b/jQuery-File-Upload.MVC3/Upload/FilesStatus.cs
index 89189fd..eabe8ed 100644
--- a/jQuery-File-Upload.MVC3/Upload/FilesStatus.cs
+++ b/jQuery-File-Upload.MVC3/Upload/FilesStatus.cs
@@ -1,10 +1,16 @@
 using System;
 using System.IO;
+using System.Linq;
 
 namespace jQuery_File_Upload.MVC3.Upload
 {
-    public class FilesStatus
-    {
+    public class FilesStatus
+    {
+        private static readonly string[] ImageExtensions = new[]
+            {
+                ".gif", ".jpg", ".png"
+            };
+
         public const string HandlerPath = "/Upload/";
 
         public string group { get; set; }
@@ -41,11 +47,13 @@ private void SetValues(string fileName, int fileLength, string fullPath)
             else thumbnail_url = @"data:image/png;base64," + EncodeFile(fullPath);
         }
 
-        private bool IsImage(string ext)
-        {
-            return ext == ".gif" || ext == ".jpg" || ext == ".png";
-        }
-
+        private bool IsImage(string ext)
+        {
+            string lowercaseExtension = ext.ToLowerInvariant();
+
+            return ImageExtensions.Contains(lowercaseExtension);
+        }
+
         private string EncodeFile(string fileName)
         {
             return Convert.ToBase64String(System.IO.File.ReadAllBytes(fileName));