diff --git a/changes/4219.fix.md b/changes/4219.fix.md
new file mode 100644
index 00000000000..3bc78045d3c
--- /dev/null
+++ b/changes/4219.fix.md
@@ -0,0 +1 @@
+Fix `None` network deletion error when deleting session.
diff --git a/src/ai/backend/manager/registry.py b/src/ai/backend/manager/registry.py
index 235ab2ee574..0e095a35916 100644
--- a/src/ai/backend/manager/registry.py
+++ b/src/ai/backend/manager/registry.py
@@ -2705,7 +2705,8 @@ async def _fetch_session() -> tuple[SessionRow, str | None]:
                         session.main_kernel.agent,
                         order_key=str(session.main_kernel.session_id),
                     ) as rpc:
-                        await rpc.call.destroy_local_network(network_ref_name)
+                        if network_ref_name:
+                            await rpc.call.destroy_local_network(network_ref_name)
                 except Exception:
                     log.exception(f"Failed to destroy the agent-local network {network_ref_name}")
             elif session.cluster_mode == ClusterMode.MULTI_NODE: