diff --git a/youtube_dl/utils.py b/youtube_dl/utils.py
index bcea188a3..548ce12e2 100644
--- a/youtube_dl/utils.py
+++ b/youtube_dl/utils.py
@@ -2112,8 +2112,8 @@ def js_to_json(code):
     return re.sub(r'''(?sx)
         "(?:[^"\\]*(?:\\\\|\\['"nurtbfx/\n]))*[^"\\]*"|
         '(?:[^'\\]*(?:\\\\|\\['"nurtbfx/\n]))*[^'\\]*'|
-        ,(?=(\s|(/\*((?!\*/)(\n|.))*\*/))*[\]}])|
-        /\*((?!\*/)(\n|.))*\*/|[a-zA-Z_][.a-zA-Z_0-9]*|
+        ,(?=(?:\s|(?:/\*(?:(?!\*/)(?:\n|.))*\*/))*[\]}])|
+        /\*(?:(?!\*/)(?:\n|.))*\*/|[a-zA-Z_][.a-zA-Z_0-9]*|
         \b(?:0[xX][0-9a-fA-F]+|0+[0-7]+)(?:\s*:)?|
         [0-9]+(?=\s*:)
         ''', fix_kv, code)