diff --git a/changelog.d/20107.misc b/changelog.d/20107.misc
new file mode 100644
index 0000000000..fb7a845252
--- /dev/null
+++ b/changelog.d/20107.misc
@@ -0,0 +1 @@
+Declare types that already appear in the module API's public signatures (such as `Requester`, `SynapseRequest` and `UserInfo`) in `synapse.module_api.__all__`.
diff --git a/synapse/module_api/__init__.py b/synapse/module_api/__init__.py
index 1be0e9fd91..58ccddc792 100644
--- a/synapse/module_api/__init__.py
+++ b/synapse/module_api/__init__.py
@@ -194,14 +194,21 @@ __all__ = [
     "run_in_background",
     "run_as_background_process",
     "cached",
+    "CachedFunction",
     "NOT_SPAM",
     "UserID",
+    "DomainSpecificString",
     "DatabasePool",
     "LoggingTransaction",
     "DirectServeHtmlResource",
     "DirectServeJsonResource",
+    "SimpleHttpClient",
+    "SynapseRequest",
     "ModuleApi",
+    "AccountDataManager",
+    "PublicRoomListManager",
     "PRESENCE_ALL_USERS",
+    "UserPresenceState",
     "LoginResponse",
     "JsonDict",
     "JsonMapping",
@@ -209,7 +216,13 @@ __all__ = [
     "StateMap",
     "ProfileInfo",
     "RoomAlias",
+    "RoomID",
+    "Requester",
+    "UserInfo",
+    "UserIpAndAgent",
     "UserProfile",
+    "Absent",
+    "AbsentType",
     "RatelimitOverride",
     "MediaUploadLimit",
 ]