diff --git a/yt_dlp/extractor/dropbox.py b/yt_dlp/extractor/dropbox.py
index 4a67bb92b..9326c00f6 100644
--- a/yt_dlp/extractor/dropbox.py
+++ b/yt_dlp/extractor/dropbox.py
@@ -52,7 +52,7 @@ def _real_extract(self, url):
 
         for part in self._yield_decoded_parts(webpage):
             if '/sm/password' in part:
-                content_id = self._search_regex(r'content_id=([\w-]+)', part, 'content ID')
+                content_id = self._search_regex(r'content_id=([\w.+=/-]+)', part, 'content ID')
                 break
 
         if content_id and not self._get_cookies('https://dropbox.com/').get('sm_auth'):