diff --git a/lix/libutil/cgroup.cc b/lix/libutil/cgroup.cc
index a4d2c7518..f05dd6a1c 100644
--- a/lix/libutil/cgroup.cc
+++ b/lix/libutil/cgroup.cc
@@ -330,7 +330,7 @@ void AutoDestroyCgroup::cleansePreviousInstancesAndRecordOurself(
     }
 
     writeFile(cgroupFile, std::get<std::filesystem::path>(cgroup_).string());
-    stateRecord = AutoDelete(cgroupFile, false);
+    stateRecord.reset(cgroupFile, false);
 }
 
 void AutoDestroyCgroup::adoptProcess(int pid)
diff --git a/lix/libutil/file-system.hh b/lix/libutil/file-system.hh
index 67f7102eb..69798cb5f 100644
--- a/lix/libutil/file-system.hh
+++ b/lix/libutil/file-system.hh
@@ -273,6 +273,8 @@ class AutoDelete
     bool del;
     bool recursive;
 public:
+    KJ_DISALLOW_COPY_AND_MOVE(AutoDelete);
+
     AutoDelete();
     AutoDelete(const Path & p, bool recursive = true);
     ~AutoDelete();