diff --git a/third_party/nix/src/libexpr/attr-set.cc b/third_party/nix/src/libexpr/attr-set.cc
index 5ef63a129..31b5bdcef 100644
--- a/third_party/nix/src/libexpr/attr-set.cc
+++ b/third_party/nix/src/libexpr/attr-set.cc
@@ -131,7 +131,6 @@ void BTreeBindings::merge(Bindings& other) {
 
 class VectorBindings : public Bindings {
  public:
-  VectorBindings() {};
   VectorBindings(size_t capacity) : attributes_() {
     attributes_.reserve(capacity);
   };
@@ -145,6 +144,8 @@ class VectorBindings : public Bindings {
   void merge(Bindings& other) override;
   [[deprecated]] virtual std::vector<const Attr*> lexicographicOrder() override;
 
+  VectorBindings(VectorBindings&) = delete;
+
  private:
   AttributeVector attributes_;
 };