diff --git a/test/test_youtube_signature.py b/test/test_youtube_signature.py
index 2a99436a6..13436f088 100644
--- a/test/test_youtube_signature.py
+++ b/test/test_youtube_signature.py
@@ -73,6 +73,11 @@ _SIG_TESTS = [
         '2aq0aqSyOoJXtK73m-uME_jv7-pT15gOFC02RFkGMqWpzEICs69VdbwQ0LDp1v7j8xx92efCJlYFYb1sUkkBSPOlPmXgIARw8JQ0qOAOAA',
         'MyOSJXtKI3m-uME_jv7-pT12gOFC02RFkGoqWpzE0Cs69VdbwQ0LDp1v7j8xx92efCJlYFYb1sUkkBSPOlPmXgIARw8JQ0qOAOAA',
     ),
+    (
+        'https://www.youtube.com/s/player/2f1832d2/player_ias.vflset/en_US/base.js',
+        '2aq0aqSyOoJXtK73m-uME_jv7-pT15gOFC02RFkGMqWpzEICs69VdbwQ0LDp1v7j8xx92efCJlYFYb1sUkkBSPOlPmXgIARw8JQ0qOAOAA',
+        '0QJ8wRAIgXmPlOPSBkkUs1bYFYlJCfe29xxAj7v1pDL0QwbdV96sCIEzpWqMGkFR20CFOg51Tp-7vj_EMu-m37KtXJ2OySqa0q',
+    ),
 ]
 
 _NSIG_TESTS = [
@@ -192,6 +197,10 @@ _NSIG_TESTS = [
         'https://www.youtube.com/s/player/3bb1f723/player_ias.vflset/en_US/base.js',
         'gK15nzVyaXE9RsMP3z', 'ZFFWFLPWx9DEgQ',
     ),
+    (
+        'https://www.youtube.com/s/player/2f1832d2/player_ias.vflset/en_US/base.js',
+        'YWt1qdbe8SAfkoPHW5d', 'RrRjWQOJmBiP',
+    ),
 ]
 
 
diff --git a/yt_dlp/extractor/youtube.py b/yt_dlp/extractor/youtube.py
index 7eb522a47..e4904965d 100644
--- a/yt_dlp/extractor/youtube.py
+++ b/yt_dlp/extractor/youtube.py
@@ -3127,9 +3127,9 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
         # ;N&&(N=sig(decodeURIComponent(N)),J.set(R,encodeURIComponent(N)));return J};
         # {var H=u,k=f.sp,v=sig(decodeURIComponent(f.s));H.set(k,encodeURIComponent(v))}
         funcname = self._search_regex(
-            (r'\b(?P<var>[a-zA-Z0-9$]+)&&\((?P=var)=(?P<sig>[a-zA-Z0-9$]{2,})\(decodeURIComponent\((?P=var)\)\)',
-             r'(?P<sig>[a-zA-Z0-9$]+)\s*=\s*function\(\s*(?P<arg>[a-zA-Z0-9$]+)\s*\)\s*{\s*(?P=arg)\s*=\s*(?P=arg)\.split\(\s*""\s*\)\s*;\s*[^}]+;\s*return\s+(?P=arg)\.join\(\s*""\s*\)',
-             r'(?:\b|[^a-zA-Z0-9$])(?P<sig>[a-zA-Z0-9$]{2,})\s*=\s*function\(\s*a\s*\)\s*{\s*a\s*=\s*a\.split\(\s*""\s*\)(?:;[a-zA-Z0-9$]{2}\.[a-zA-Z0-9$]{2}\(a,\d+\))?',
+            (r'\b(?P<var>[a-zA-Z0-9_$]+)&&\((?P=var)=(?P<sig>[a-zA-Z0-9_$]{2,})\(decodeURIComponent\((?P=var)\)\)',
+             r'(?P<sig>[a-zA-Z0-9_$]+)\s*=\s*function\(\s*(?P<arg>[a-zA-Z0-9_$]+)\s*\)\s*{\s*(?P=arg)\s*=\s*(?P=arg)\.split\(\s*""\s*\)\s*;\s*[^}]+;\s*return\s+(?P=arg)\.join\(\s*""\s*\)',
+             r'(?:\b|[^a-zA-Z0-9_$])(?P<sig>[a-zA-Z0-9_$]{2,})\s*=\s*function\(\s*a\s*\)\s*{\s*a\s*=\s*a\.split\(\s*""\s*\)(?:;[a-zA-Z0-9_$]{2}\.[a-zA-Z0-9_$]{2}\(a,\d+\))?',
              # Old patterns
              r'\b[cs]\s*&&\s*[adf]\.set\([^,]+\s*,\s*encodeURIComponent\s*\(\s*(?P<sig>[a-zA-Z0-9$]+)\(',
              r'\b[a-zA-Z0-9]+\s*&&\s*[a-zA-Z0-9]+\.set\([^,]+\s*,\s*encodeURIComponent\s*\(\s*(?P<sig>[a-zA-Z0-9$]+)\(',