1 files changed, 4 insertions, 2 deletions
diff --git a/tests/server.py b/tests/server.py
index 6ce2a17bf4..aaa5ca3e74 100644
--- a/tests/server.py
+++ b/tests/server.py
@@ -22,7 +22,6 @@ import warnings
 from collections import deque
 from io import SEEK_END, BytesIO
 from typing import (
-    AnyStr,
     Callable,
     Dict,
     Iterable,
@@ -86,6 +85,9 @@ from tests.utils import (
 
 logger = logging.getLogger(__name__)
 
+# the type of thing that can be passed into `make_request` in the headers list
+CustomHeaderType = Tuple[Union[str, bytes], Union[str, bytes]]
+
 
 class TimedOutException(Exception):
     """
@@ -260,7 +262,7 @@ def make_request(
     federation_auth_origin: Optional[bytes] = None,
     content_is_form: bool = False,
     await_result: bool = True,
-    custom_headers: Optional[Iterable[Tuple[AnyStr, AnyStr]]] = None,
+    custom_headers: Optional[Iterable[CustomHeaderType]] = None,
     client_ip: str = "127.0.0.1",
 ) -> FakeChannel:
     """