diff --git a/includes/ApiCategoryTree.php b/includes/ApiCategoryTree.php
index fcd367a1..6b4968f3 100644
--- a/includes/ApiCategoryTree.php
+++ b/includes/ApiCategoryTree.php
@@ -147,7 +147,7 @@ class ApiCategoryTree extends ApiBase {
 			),
 			$this->wanCache::TTL_DAY,
 			static function () use ( $ct, $title, $depth ) {
-				return trim( $ct->renderChildren( $title, $depth ) );
+				return $ct->renderChildren( $title, $depth );
 			},
 			[
 				'touchedCallback' => function () {
diff --git a/includes/CategoryTree.php b/includes/CategoryTree.php
index 0c9188b6..1a84af84 100644
--- a/includes/CategoryTree.php
+++ b/includes/CategoryTree.php
@@ -81,14 +81,8 @@ class CategoryTree {
 	public function getTag( string $category, bool $hideroot = false, array $attr = [],
 		int $depth = 1
 	) {
-		$category = trim( $category );
-		if ( $category === '' ) {
-			return false;
-		}
-
 		$title = self::makeTitle( $category );
-
-		if ( $title === null ) {
+		if ( !$title ) {
 			return false;
 		}