diff --git a/hosts/piha/runtime/ha-diag-agent/docker-compose.override.yml b/hosts/piha/runtime/ha-diag-agent/docker-compose.override.yml
index 4d50b5a..be99311 100644
--- a/hosts/piha/runtime/ha-diag-agent/docker-compose.override.yml
+++ b/hosts/piha/runtime/ha-diag-agent/docker-compose.override.yml
@@ -1,5 +1,7 @@
 services:
   ha-diag-agent:
+    environment:
+      - NODE_NAME=piha
     # Pin events to the piha-specific subdirectory; overrides the ${NODE_NAME}
     # variable substitution in the base compose file which requires a shell env var.
     volumes: