diff --git a/stdlib/calendar.pyi b/stdlib/calendar.pyi
index 14d1d9075..5cc49e102 100644
--- a/stdlib/calendar.pyi
+++ b/stdlib/calendar.pyi
@@ -124,7 +124,7 @@ class HTMLCalendar(Calendar):
     def formatyear(self, theyear: int, width: int = 3) -> str: ...
     def formatyearpage(
         self, theyear: int, width: int = 3, css: str | None = "calendar.css", encoding: str | None = None
-    ) -> str: ...
+    ) -> bytes: ...
 
 class different_locale:
     def __init__(self, locale: _LocaleType) -> None: ...