diff --git a/filesystem/File.php b/filesystem/File.php
index 68da17445..01d89af88 100644
--- a/filesystem/File.php
+++ b/filesystem/File.php
@@ -411,7 +411,7 @@ class File extends DataObject {
 	 * @return String
 	 */
 	public function appCategory() {
-		return self::get_app_category($this->Extension);
+		return self::get_app_category($this->getExtension());
 	}
 
 	public function CMSThumbnail() {
@@ -426,7 +426,7 @@ class File extends DataObject {
 	 * @return String 
 	 */
 	public function Icon() {
-		$ext = $this->Extension;
+		$ext = strtolower($this->getExtension());
 		if(!Director::fileExists(FRAMEWORK_DIR . "/images/app_icons/{$ext}_32.gif")) {
 			$ext = $this->appCategory();
 		}