1 files changed, 14 insertions, 4 deletions
diff --git a/synapse/handlers/set_password.py b/synapse/handlers/set_password.py
index 29cc03d71d..94301add9e 100644
--- a/synapse/handlers/set_password.py
+++ b/synapse/handlers/set_password.py
@@ -36,10 +36,17 @@ class SetPasswordHandler:
     def __init__(self, hs: "HomeServer"):
         self.store = hs.get_datastores().main
         self._auth_handler = hs.get_auth_handler()
-        # This can only be instantiated on the main process.
-        device_handler = hs.get_device_handler()
-        assert isinstance(device_handler, DeviceHandler)
-        self._device_handler = device_handler
+
+        # We don't need the device handler if password changing is disabled.
+        # This allows us to instantiate the SetPasswordHandler on the workers
+        # that have admin APIs for MAS
+        if self._auth_handler.can_change_password():
+            # This can only be instantiated on the main process.
+            device_handler = hs.get_device_handler()
+            assert isinstance(device_handler, DeviceHandler)
+            self._device_handler: Optional[DeviceHandler] = device_handler
+        else:
+            self._device_handler = None
 
     async def set_password(
         self,
@@ -51,6 +58,9 @@ class SetPasswordHandler:
         if not self._auth_handler.can_change_password():
             raise SynapseError(403, "Password change disabled", errcode=Codes.FORBIDDEN)
 
+        # We should have this available only if password changing is enabled.
+        assert self._device_handler is not None
+
         try:
             await self.store.user_set_password_hash(user_id, password_hash)
         except StoreError as e: