diff --git a/lib/charms/opensearch/v0/opensearch_base_charm.py b/lib/charms/opensearch/v0/opensearch_base_charm.py
index cb8eac84c..641f7cdf5 100644
--- a/lib/charms/opensearch/v0/opensearch_base_charm.py
+++ b/lib/charms/opensearch/v0/opensearch_base_charm.py
@@ -816,6 +816,8 @@ def _post_start_init(self, event: EventBase):
         # clear waiting to start status
         self.status.clear(WaitingToStart)
 
+        self.unit.open_port("tcp", 9200)
+
         # update the peer cluster rel data with new IP in case of main cluster manager
         if self.opensearch_peer_cm.deployment_desc().typ != DeploymentType.OTHER:
             if self.opensearch_peer_cm.is_peer_cluster_orchestrator_relation_set():