diff --git a/classes/api.php b/classes/api.php
index 1cef9c482..539aa334b 100755
--- a/classes/api.php
+++ b/classes/api.php
@@ -1,7 +1,7 @@
 <?php
 class API extends Handler {
 
-	const API_LEVEL  = 17;
+	const API_LEVEL  = 18;
 
 	const STATUS_OK  = 0;
 	const STATUS_ERR = 1;
@@ -186,11 +186,9 @@ class API extends Handler {
 	}
 
 	function getHeadlines(): bool {
-		$feed_id = clean($_REQUEST["feed_id"]);
-		if ($feed_id !== "" && is_numeric($feed_id)) {
-
-			$feed_id = (int) $feed_id;
+		$feed_id = clean($_REQUEST["feed_id"] ?? "");
 
+		if (!empty($feed_id)) {
 			$limit = (int)clean($_REQUEST["limit"] ?? 0 );
 
 			if (!$limit || $limit >= 200) $limit = 200;
@@ -632,9 +630,10 @@ class API extends Handler {
 	}
 
 	/**
+	 * @param string|int $feed_id
 	 * @return array{0: array<int, array<string, mixed>>, 1: array<string, mixed>} $headlines, $headlines_header
 	 */
-	private static function _api_get_headlines(int $feed_id, int $limit, int $offset,
+	private static function _api_get_headlines(mixed $feed_id, int $limit, int $offset,
 				string $filter, bool $is_cat, bool $show_excerpt, bool $show_content, ?string $view_mode, string $order,
 				bool $include_attachments, int $since_id, string $search = "", bool $include_nested = false,
 				bool $sanitize_content = true, bool $force_update = false, int $excerpt_length = 100, ?int $check_first_id = null,
diff --git a/classes/feeds.php b/classes/feeds.php
index 6f9cca8b2..af2ee1a8c 100755
--- a/classes/feeds.php
+++ b/classes/feeds.php
@@ -18,9 +18,10 @@ class Feeds extends Handler_Protected {
 	}
 
 	/**
+	 * @param string|int $feed
 	 * @return array{0: array<int, int>, 1: int, 2: int, 3: bool, 4: array<string, mixed>} $topmost_article_ids, $headlines_count, $feed, $disable_cache, $reply
 	 */
-	private function _format_headlines_list(int $feed, string $method, string $view_mode, int $limit, bool $cat_view,
+	private function _format_headlines_list(mixed $feed, string $method, string $view_mode, int $limit, bool $cat_view,
 					int $offset, string $override_order, bool $include_children, ?int $check_first_id = null,
 					bool $skip_first_id_check, string $order_by): array {
 
@@ -1213,7 +1214,10 @@ class Feeds extends Handler_Protected {
 		}
 	}
 
-	static function _get_title(int $id, bool $cat = false): string {
+	/**
+	 * @param string|int $id
+	 */
+	static function _get_title(mixed $id, bool $cat = false): string {
 		$pdo = Db::pdo();
 
 		if ($cat) {