diff --git a/play-dl/YouTube/utils/extractor.ts b/play-dl/YouTube/utils/extractor.ts
index 1d7addf..d69fe0c 100644
--- a/play-dl/YouTube/utils/extractor.ts
+++ b/play-dl/YouTube/utils/extractor.ts
@@ -100,6 +100,8 @@ export function extractID(url: string): string {
  * @returns Video Basic Info {@link InfoData}.
  */
 export async function video_basic_info(url: string, options: InfoOptions = {}): Promise<InfoData> {
+    if (url === null || url === undefined || typeof url !== 'string')
+        throw new Error('url parameter is not a URL string or a string of HTML');
     let body: string;
     if (options.htmldata) {
         body = url;
@@ -205,6 +207,8 @@ export async function video_basic_info(url: string, options: InfoOptions = {}):
  * @returns Deciphered Video Info {@link StreamInfoData}.
  */
 export async function video_stream_info(url: string, options: InfoOptions = {}): Promise<StreamInfoData> {
+    if (url === null || url === undefined || typeof url !== 'string')
+        throw new Error('url parameter is not a URL string or a string of HTML');
     let body: string;
     if (options.htmldata) {
         body = url;