diff --git a/hive-c0re/src/migrate.rs b/hive-c0re/src/migrate.rs
index 044b572a..9ed28ecc 100644
--- a/hive-c0re/src/migrate.rs
+++ b/hive-c0re/src/migrate.rs
@@ -187,9 +187,19 @@ async fn rename_manager_container(coord: &Arc<Coordinator>) {
     tracing::info!("migration phase 5: renaming root container to h-root");
     let _guard = coord.transient_guard(MANAGER_NAME, crate::coordinator::TransientKind::Rebuilding);
 
-    // Stop the old container.
-    if let Err(e) = Command::new("nixos-container").args(["stop", "root"]).status().await {
-        tracing::warn!(error = ?e, "migration phase 5: nixos-container stop root failed");
+    // Stop the old container. Abort if stop fails — continuing with a
+    // running `root` and then starting `h-root` risks two manager
+    // instances racing for the same broker / state files.
+    match Command::new("nixos-container").args(["stop", "root"]).status().await {
+        Ok(s) if s.success() => {}
+        Ok(s) => {
+            tracing::warn!(status = %s, "migration phase 5: nixos-container stop root failed — aborting");
+            return;
+        }
+        Err(e) => {
+            tracing::warn!(error = ?e, "migration phase 5: nixos-container stop root failed — aborting");
+            return;
+        }
     }
 
     // Copy conf file.
@@ -220,6 +230,12 @@ async fn rename_manager_container(coord: &Arc<Coordinator>) {
 
     tracing::info!("migration phase 5: root container renamed to h-root");
     let _ = std::fs::write(hroot_rename_marker(), b"done\n");
+    // Clean up the old conf file so `nixos-container list` doesn't show
+    // a stale stopped `root` entry. Best-effort; a failure here is
+    // harmless — h-root is already running and the marker is written.
+    if let Err(e) = std::fs::remove_file(&old_conf) {
+        tracing::warn!(error = ?e, "migration phase 5: remove old root.conf failed (non-fatal)");
+    }
 }
 
 async fn enumerate_agents() -> Vec<String> {