diff --git a/changelog.d/17568.bugfix b/changelog.d/17568.bugfix
new file mode 100644
index 00000000000..71a1f129154
--- /dev/null
+++ b/changelog.d/17568.bugfix
@@ -0,0 +1 @@
+Fix fetching federation signing keys from servers that omit `old_verify_keys`. Contributed by @tulir @ Beeper.
diff --git a/synapse/crypto/keyring.py b/synapse/crypto/keyring.py
index 8c301e077c2..643d2d4e66d 100644
--- a/synapse/crypto/keyring.py
+++ b/synapse/crypto/keyring.py
@@ -589,7 +589,7 @@ async def process_v2_response(
                 % (server_name,)
             )
 
-        for key_id, key_data in response_json["old_verify_keys"].items():
+        for key_id, key_data in response_json.get("old_verify_keys", {}).items():
             if is_signing_algorithm_supported(key_id):
                 key_base64 = key_data["key"]
                 key_bytes = decode_base64(key_base64)