diff --git a/engine/core/session.py b/engine/core/session.py
index 1cfaeac..4134f1e 100644
--- a/engine/core/session.py
+++ b/engine/core/session.py
@@ -770,7 +770,14 @@ class Session:
             if key == "services" and isinstance(value, dict):
                 existing = merged.get("services")
                 merged_services = dict(existing) if isinstance(existing, dict) else {}
-                merged_services.update(value)
+                for service_name, service_payload in value.items():
+                    current_payload = merged_services.get(service_name)
+                    if isinstance(current_payload, dict) and isinstance(service_payload, dict):
+                        next_payload = dict(current_payload)
+                        next_payload.update(service_payload)
+                        merged_services[service_name] = next_payload
+                    else:
+                        merged_services[service_name] = service_payload
                 merged["services"] = merged_services
             else:
                 merged[key] = value