diff --git a/synapse/handlers/register.py b/synapse/handlers/register.py
index c200e29569..c49db83ce7 100644
--- a/synapse/handlers/register.py
+++ b/synapse/handlers/register.py
@@ -630,7 +630,9 @@ class RegistrationHandler:
         """
         await self._auto_join_rooms(user_id)
 
-    async def appservice_register(self, user_localpart: str, as_token: str) -> str:
+    async def appservice_register(
+        self, user_localpart: str, as_token: str
+    ) -> Tuple[str, ApplicationService]:
         user = UserID(user_localpart, self.hs.hostname)
         user_id = user.to_string()
         service = self.store.get_app_service_by_token(as_token)
@@ -653,7 +655,7 @@ class RegistrationHandler:
             appservice_id=service_id,
             create_profile_with_displayname=user.localpart,
         )
-        return user_id
+        return (user_id, service)
 
     def check_user_id_not_appservice_exclusive(
         self, user_id: str, allowed_appservice: Optional[ApplicationService] = None
diff --git a/synapse/rest/client/register.py b/synapse/rest/client/register.py
index 61e1436841..ad76f188ab 100644
--- a/synapse/rest/client/register.py
+++ b/synapse/rest/client/register.py
@@ -771,9 +771,12 @@ class RegisterRestServlet(RestServlet):
         body: JsonDict,
         should_issue_refresh_token: bool = False,
     ) -> JsonDict:
-        user_id = await self.registration_handler.appservice_register(
+        user_id, appservice = await self.registration_handler.appservice_register(
             username, as_token
         )
+        if appservice.msc4190_device_management:
+            body["inhibit_login"] = True
+
         return await self._create_registration_details(
             user_id,
             body,
@@ -937,7 +940,7 @@ class RegisterAppServiceOnlyRestServlet(RestServlet):
 
         as_token = self.auth.get_access_token_from_request(request)
 
-        user_id = await self.registration_handler.appservice_register(
+        user_id, _ = await self.registration_handler.appservice_register(
             desired_username, as_token
         )
         return 200, {"user_id": user_id}