1 files changed, 3 insertions, 4 deletions
diff --git a/synapse/util/iterutils.py b/synapse/util/iterutils.py
index b73f690b88..0a6a30aab2 100644
--- a/synapse/util/iterutils.py
+++ b/synapse/util/iterutils.py
@@ -30,14 +30,13 @@ from typing import (
     Iterator,
     List,
     Mapping,
+    Protocol,
     Set,
     Sized,
     Tuple,
     TypeVar,
 )
 
-from typing_extensions import Protocol
-
 T = TypeVar("T")
 S = TypeVar("S", bound="_SelfSlice")
 
@@ -115,7 +114,7 @@ def sorted_topologically(
 
     # This is implemented by Kahn's algorithm.
 
-    degree_map = {node: 0 for node in nodes}
+    degree_map = dict.fromkeys(nodes, 0)
     reverse_graph: Dict[T, Set[T]] = {}
 
     for node, edges in graph.items():
@@ -165,7 +164,7 @@ def sorted_topologically_batched(
     persisted.
     """
 
-    degree_map = {node: 0 for node in nodes}
+    degree_map = dict.fromkeys(nodes, 0)
     reverse_graph: Dict[T, Set[T]] = {}
 
     for node, edges in graph.items():