diff --git a/backend/mpc-system/docker-compose.yml b/backend/mpc-system/docker-compose.yml
index 88d11cf7..81db7923 100644
--- a/backend/mpc-system/docker-compose.yml
+++ b/backend/mpc-system/docker-compose.yml
@@ -255,6 +255,7 @@ services:
       MPC_API_KEY: ${MPC_API_KEY}
       # Party identity for Message Router registration
       PARTY_ID: delegate-party
+      PARTY_ROLE: delegate
     depends_on:
       session-coordinator:
         condition: service_healthy