diff --git a/modules/mesh-knowledge/README.md b/modules/mesh-knowledge/README.md
index ea173edf..c0b75e00 100644
--- a/modules/mesh-knowledge/README.md
+++ b/modules/mesh-knowledge/README.md
@@ -131,7 +131,8 @@ the consolidated schema for a fresh database is `schema.sql`. A test holds the t
   refuses to serve while the schema is behind.
 - **`prepare`** (run once): brings the schema to this version.
 - **`keep`** (judged by its unit): judges the whole record set every five minutes and keeps the findings.
-- **`watch`** (judged by `knowledge_health`): every minute, reads whether the database serves and what the
+- **`watch`** (judged by `knowledge_health`, run as the machine's account, the one the runtime runs the bundle
+  as, so the tool can read what it writes): every minute, reads whether the database serves and what the
   findings say, and leaves its verdict in `${dir:state}/health.json`. That is the file the health tool answers
   from. A verdict older than three minutes is unhealthy.
 
diff --git a/modules/mesh-knowledge/cmd/mesh-knowledge/manifest_test.go b/modules/mesh-knowledge/cmd/mesh-knowledge/manifest_test.go
index bee4ab69..1df095fc 100644
--- a/modules/mesh-knowledge/cmd/mesh-knowledge/manifest_test.go
+++ b/modules/mesh-knowledge/cmd/mesh-knowledge/manifest_test.go
@@ -124,6 +124,12 @@ func TestItsProcessesAreThePreparationTheActAndTheJudge(t *testing.T) {
 	if watch["env"].(map[string]any)["MESH_KNOWLEDGE_STATUS"] != m.Build.Artifacts[0].Env["MESH_KNOWLEDGE_STATUS"] {
 		t.Fatal("watch writes another status file than the health tool reads")
 	}
+	// The health tool reads the status file as the account the runtime runs the bundle as, and the mesh gives that
+	// account the state directory (and nothing a process writes there later). A watch running as root wrote the
+	// file root's, 0600, and the tool could not open it (hq issue 479): watch runs as that account, as zfs's does.
+	if watch["user"] != "${machine:account}" {
+		t.Fatalf("watch runs as %v, not as the account the health tool reads its verdict as", watch["user"])
+	}
 	settings := byID["settings"]
 	var s Settings
 	if err := json.Unmarshal([]byte(settings["content"].(string)), &s); err != nil || s.JudgeModel == "" || s.ReservedFor != "168h" {
diff --git a/modules/mesh-knowledge/module.json b/modules/mesh-knowledge/module.json
index df9f51ef..10c2167c 100644
--- a/modules/mesh-knowledge/module.json
+++ b/modules/mesh-knowledge/module.json
@@ -145,6 +145,7 @@
         "./mesh-knowledge",
         "watch"
       ],
+      "user": "${machine:account}",
       "env": {
         "DATABASE_URL_FILE": "${dir:state}/database.url",
         "MESH_KNOWLEDGE_STATUS": "${dir:state}/health.json"