diff --git a/stubs/requests/requests/sessions.pyi b/stubs/requests/requests/sessions.pyi
index 96321399d..7e7d6e902 100644
--- a/stubs/requests/requests/sessions.pyi
+++ b/stubs/requests/requests/sessions.pyi
@@ -66,16 +66,8 @@ _Params: TypeAlias = Union[
     str | bytes,
 ]
 _TextMapping: TypeAlias = MutableMapping[str, str]
-_HeadersMapping: TypeAlias = MutableMapping[str, str] | MutableMapping[str, bytes] | MutableMapping[str, str | bytes]
-_HeadersUpdateMapping: TypeAlias = (
-    MutableMapping[str, str]
-    | MutableMapping[str, bytes]
-    | MutableMapping[str, None]
-    | MutableMapping[str, str | bytes]
-    | MutableMapping[str, str | None]
-    | MutableMapping[str, bytes | None]
-    | MutableMapping[str, str | bytes | None]
-)
+_HeadersMapping: TypeAlias = Mapping[str, str | bytes]
+_HeadersUpdateMapping: TypeAlias = Mapping[str, str | bytes | None]
 _Timeout: TypeAlias = Union[float, tuple[float, float], tuple[float, None]]
 _Verify: TypeAlias = bool | str