diff --git a/yt_dlp/extractor/vidlii.py b/yt_dlp/extractor/vidlii.py
index 5933783ae..cde4274d9 100644
--- a/yt_dlp/extractor/vidlii.py
+++ b/yt_dlp/extractor/vidlii.py
@@ -70,6 +70,7 @@ class VidLiiIE(InfoExtractor):
             r'src\s*:\s*(["\'])(?P<url>(?:https?://)?(?:(?!\1).)+)\1',
             webpage) or []]
         for source in sources:
+            source = urljoin(url, source)
             height = int(self._search_regex(r'(\d+).mp4', source, 'height', default=360))
             if self._request_webpage(HEADRequest(source), video_id, f'Checking {height}p url', errnote=False):
                 formats.append({