diff --git a/code/controllers/AssetAdmin.php b/code/controllers/AssetAdmin.php
index b2029230..eff6eb03 100644
--- a/code/controllers/AssetAdmin.php
+++ b/code/controllers/AssetAdmin.php
@@ -120,7 +120,11 @@ JS
 
 		// Category filter
 		if(isset($params['AppCategory'])) {
-			$exts = (isset(File::$app_categories[$params['AppCategory']])) ? File::$app_categories[$params['AppCategory']] : array();
+			if(isset(File::$app_categories[$params['AppCategory']])) {
+				$exts = File::$app_categories[$params['AppCategory']];
+			} else {
+				$exts = array();
+			}
 			$categorySQLs = array();
 			foreach($exts as $ext) $categorySQLs[] = '"File"."Name" LIKE \'%.' . $ext . '\'';
 			// TODO Use DataList->filterAny() once OR connectives are implemented properly