diff --git a/stacks/arbo/compose.yaml b/stacks/arbo/compose.yaml
index a4b38cb..a990c1a 100644
--- a/stacks/arbo/compose.yaml
+++ b/stacks/arbo/compose.yaml
@@ -68,6 +68,13 @@ services:
       - ${ARBO_CATALOG_DIR:-/worktank/arbo/repo}/catalog:/app/catalog:ro
       - ${ARBO_CATALOG_DIR:-/worktank/arbo/repo}/graphs:/app/graphs:ro
       - ${ARBO_CATALOG_DIR:-/worktank/arbo/repo}/frontend:/app/frontend:ro
+      # pyproject.toml rides the same checkout mount so /healthz catalog_version
+      # reports the MOUNTED repo version (read from /app/pyproject.toml), not the
+      # baked importlib.metadata one — otherwise a catalog/frontend-only webhook
+      # deploy (no image rebuild) leaves the reported version stale (comfy-dev
+      # v0.12.5 observability fix, 2026-06-16). Activated on the next engine
+      # recreate; the code falls back cleanly if the file is absent.
+      - ${ARBO_CATALOG_DIR:-/worktank/arbo/repo}/pyproject.toml:/app/pyproject.toml:ro
     # python-based (the slim image ships no curl/wget; python is always present):
     healthcheck:
       test: ["CMD-SHELL", "python -c \"import urllib.request,sys; sys.exit(0 if urllib.request.urlopen('http://localhost:8200/healthz').status==200 else 1)\""]