diff --git a/spire/entrypoint.agent.sh b/spire/entrypoint.agent.sh
index 51dec50..4f6d443 100755
--- a/spire/entrypoint.agent.sh
+++ b/spire/entrypoint.agent.sh
@@ -29,7 +29,7 @@ if [ ! -f /opt/spire/data/agent/svid.key ] && [ ! -f /opt/spire/data/agent/agent
     JOIN_TOKEN=$(cat /opt/spire/data/bootstrap_token | tr -d ' \r\n')
     echo "[SPIRE Agent] Joining SPIRE cluster with token..."
     rm -f /opt/spire/data/bootstrap_token
-    exec /usr/local/bin/spire-agent "$@" -join_token "$JOIN_TOKEN"
+    exec /usr/local/bin/spire-agent "$@" -joinToken "$JOIN_TOKEN"
   else
     echo "[SPIRE Agent] Warning: No bootstrap_token found after 30s. Attempting standard startup..."
   fi