diff --git a/changelog.d/4765.misc b/changelog.d/4765.misc
new file mode 100644
index 000000000..c273fd0cc
--- /dev/null
+++ b/changelog.d/4765.misc
@@ -0,0 +1 @@
+Minor docstring fixes for MatrixFederationAgent.
\ No newline at end of file
diff --git a/synapse/http/federation/matrix_federation_agent.py b/synapse/http/federation/matrix_federation_agent.py
index 384d8a37a..1334c630c 100644
--- a/synapse/http/federation/matrix_federation_agent.py
+++ b/synapse/http/federation/matrix_federation_agent.py
@@ -68,9 +68,13 @@ class MatrixFederationAgent(object):
             TLS policy to use for fetching .well-known files. None to use a default
             (browser-like) implementation.
 
-        srv_resolver (SrvResolver|None):
+        _srv_resolver (SrvResolver|None):
             SRVResolver impl to use for looking up SRV records. None to use a default
             implementation.
+
+        _well_known_cache (TTLCache|None):
+            TTLCache impl for storing cached well-known lookups. None to use a default
+            implementation.
     """
 
     def __init__(