diff --git a/m3u8downloader/__init__.py b/m3u8downloader/__init__.py
index 260c070a890dcf7c1bff15a9d7d64570ad806e74..6a9beea82f651e38eec7867b4c22c0c4cf6907eb 100644
--- a/m3u8downloader/__init__.py
+++ b/m3u8downloader/__init__.py
@@ -1 +1 @@
-__version__ = "0.3.1"
+__version__ = "0.4.0"
diff --git a/m3u8downloader/main.py b/m3u8downloader/main.py
index 1ea4004215b5940be660870289a4aefddfe72c76..653994975db74145c2f3ed202bd199d13df4a58d 100644
--- a/m3u8downloader/main.py
+++ b/m3u8downloader/main.py
@@ -311,13 +311,24 @@ class M3u8Downloader:
 
 def main():
     parser = argparse.ArgumentParser(description="download video at m3u8 url")
+    parser.add_argument('--version', action='store_true', help='print version')
     parser.add_argument('--output', '-o', help='target video filename')
     parser.add_argument(
         '--tempdir', default='~/.cache/m3u8downloader',
         help='temp dir, used to store .ts files before combing them into mp4')
-    parser.add_argument('url', help='the m3u8 url')
+    parser.add_argument('url', nargs='?', help='the m3u8 url')
     args = parser.parse_args()
 
+    if args.version:
+        import m3u8downloader
+        print("m3u8downloader " + m3u8downloader.__version__)
+        return
+
+    if not args.url:
+        print("URL is required")
+        parser.print_help()
+        sys.exit(1)
+
     SESSION.headers.update({'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.119 Safari/537.36'})
     downloader = M3u8Downloader(args.url, args.output, args.tempdir)
     downloader.start()