diff --git a/src/specklepy/transports/server/retry_policy.py b/src/specklepy/transports/server/retry_policy.py
index 80f3ba3..da2752a 100644
--- a/src/specklepy/transports/server/retry_policy.py
+++ b/src/specklepy/transports/server/retry_policy.py
@@ -21,7 +21,7 @@ def setup_session(auth_token: str | None) -> requests.Session:
         read=3,
         connect=3,
         backoff_factor=0.5,
-        status_forcelist=(500, 502, 503, 504, 408, 429),
+        status_forcelist=(500, 502, 503, 504, 520, 408, 429),
         allowed_methods=["HEAD", "GET", "OPTIONS", "POST", "PUT", "DELETE"],
         raise_on_status=False,
     )