diff --git a/yt_dlp/extractor/nrk.py b/yt_dlp/extractor/nrk.py
index 0f72561f9..ec69a9435 100644
--- a/yt_dlp/extractor/nrk.py
+++ b/yt_dlp/extractor/nrk.py
@@ -221,7 +221,7 @@ def _real_extract(self, url):
                 'url': sub_url,
             })
 
-        chapters = None
+        chapters = []
         if data.get('skipDialogInfo'):
             chapters = [item for item in [{
                     'start_time': float_or_none(traverse_obj(data, ('skipDialogInfo', 'startIntroInSeconds'))),