diff --git a/src/petals/cli/run_server.py b/src/petals/cli/run_server.py
index d4fc999..c82ff44 100644
--- a/src/petals/cli/run_server.py
+++ b/src/petals/cli/run_server.py
@@ -122,7 +122,7 @@ def main():
                         help="Timeout (in seconds) for waiting the next step's inputs inside an inference session")
 
     group = parser.add_mutually_exclusive_group()
-    group.add_argument('--initial_peers', type=str, nargs='*', required=False, default=PUBLIC_INITIAL_PEERS,
+    group.add_argument('--initial_peers', type=str, nargs='+', required=False, default=PUBLIC_INITIAL_PEERS,
                        help='Multiaddrs of one or more DHT peers from the target swarm. Default: connects to the public swarm')
     group.add_argument('--new_swarm', action='store_true',
                        help='Start a new private swarm (i.e., do not connect to any initial peers)')