diff --git a/stdlib/bz2.pyi b/stdlib/bz2.pyi
index a7837e1b9ff8..cd11baa1a0c1 100644
--- a/stdlib/bz2.pyi
+++ b/stdlib/bz2.pyi
@@ -131,7 +131,7 @@ class BZ2File(BaseStream, IO[bytes]):
 
 @final
 class BZ2Compressor:
-    def __init__(self, compresslevel: int = ...) -> None: ...
+    def __init__(self, compresslevel: int = 9) -> None: ...
     def compress(self, data: ReadableBuffer, /) -> bytes: ...
     def flush(self) -> bytes: ...