diff --git a/yt_dlp/utils/_utils.py b/yt_dlp/utils/_utils.py
index d9d0e9040c..1d8c7e1cff 100644
--- a/yt_dlp/utils/_utils.py
+++ b/yt_dlp/utils/_utils.py
@@ -167,7 +167,7 @@ def IDENTITY(x):
 
 NUMBER_RE = r'\d+(?:\.\d+)?'
 
-WINDOWS_RESERVED_NAMES_RE = fr'({"|".join(
+WINDOWS_RESERVED_NAMES = (
     ("CON", "CONOUT$", "CONIN$", "PRN", "AUX", "CLOCK$", "NUL")
     + tuple(f"{name:s}{num:d}" for name, num in itertools.product(("COM", "LPT"), range(0, 10)))
     + tuple(
@@ -177,7 +177,8 @@ def IDENTITY(x):
             ("\N{SUPERSCRIPT ONE}", "\N{SUPERSCRIPT TWO}", "\N{SUPERSCRIPT THREE}"),
         )
     )
-)})'
+)
+WINDOWS_RESERVED_NAMES_RE = fr'({"|".join(WINDOWS_RESERVED_NAMES)})'
 
 
 @functools.cache