diff --git a/stdlib/builtins.pyi b/stdlib/builtins.pyi
index e487c76c6..1016ffdf0 100644
--- a/stdlib/builtins.pyi
+++ b/stdlib/builtins.pyi
@@ -231,7 +231,7 @@ class int:
     def __trunc__(self) -> int: ...
     def __ceil__(self) -> int: ...
     def __floor__(self) -> int: ...
-    def __round__(self, ndigits: SupportsIndex = ...) -> int: ...
+    def __round__(self, __ndigits: SupportsIndex = ...) -> int: ...
     def __getnewargs__(self) -> tuple[int]: ...
     def __eq__(self, x: object) -> bool: ...
     def __ne__(self, x: object) -> bool: ...
@@ -283,9 +283,9 @@ class float:
         def __ceil__(self) -> int: ...
         def __floor__(self) -> int: ...
     @overload
-    def __round__(self, ndigits: None = ...) -> int: ...
+    def __round__(self, __ndigits: None = ...) -> int: ...
     @overload
-    def __round__(self, ndigits: SupportsIndex) -> float: ...
+    def __round__(self, __ndigits: SupportsIndex) -> float: ...
     def __eq__(self, __x: object) -> bool: ...
     def __ne__(self, __x: object) -> bool: ...
     def __lt__(self, __x: float) -> bool: ...
diff --git a/stdlib/decimal.pyi b/stdlib/decimal.pyi
index f08ed02d6..f9c5c1262 100644
--- a/stdlib/decimal.pyi
+++ b/stdlib/decimal.pyi
@@ -93,7 +93,7 @@ class Decimal(object):
     @overload
     def __round__(self) -> int: ...
     @overload
-    def __round__(self, ndigits: int) -> Decimal: ...
+    def __round__(self, __ndigits: int) -> Decimal: ...
     def __floor__(self) -> int: ...
     def __ceil__(self) -> int: ...
     def fma(self, other: _Decimal, third: _Decimal, context: Context | None = ...) -> Decimal: ...
diff --git a/stdlib/typing.pyi b/stdlib/typing.pyi
index 9df12664b..a7986b10a 100644
--- a/stdlib/typing.pyi
+++ b/stdlib/typing.pyi
@@ -167,7 +167,7 @@ class SupportsRound(Protocol[_T_co]):
     def __round__(self) -> int: ...
     @overload
     @abstractmethod
-    def __round__(self, ndigits: int) -> _T_co: ...
+    def __round__(self, __ndigits: int) -> _T_co: ...
 
 @runtime_checkable
 class Sized(Protocol, metaclass=ABCMeta):
diff --git a/tests/stubtest_allowlists/py310.txt b/tests/stubtest_allowlists/py310.txt
index a4db6db0d..59478e1c2 100644
--- a/tests/stubtest_allowlists/py310.txt
+++ b/tests/stubtest_allowlists/py310.txt
@@ -160,5 +160,6 @@ sqlite3.dbapi2.complete_statement
 ssl.SSLContext.__new__
 ssl._create_unverified_context
 ssl.get_server_certificate
+typing.SupportsRound.__round__
 unicodedata.ucnhash_CAPI
 unittest.mock.create_autospec