diff --git a/mace/core/allocator.h b/mace/core/allocator.h
index 79efd610be61c4bde548009c9e13ec6ec8302650..67c96539065906286e649ea9efbc1bc3ca22548a 100644
--- a/mace/core/allocator.h
+++ b/mace/core/allocator.h
@@ -55,11 +55,11 @@ class CPUAllocator: public Allocator {
     return data;
   }
 
-  void Delete(void* data) {
+  void Delete(void* data) override {
     free(data);
   }
 
-  void CopyBytes(void* dst, const void* src, size_t size) {
+  void CopyBytes(void* dst, const void* src, size_t size) override {
     memcpy(dst, src, size);
   }
 };
diff --git a/mace/core/operator.h b/mace/core/operator.h
index 6ac672f641b27b4d2eaa39dcbba9dc1dc590a051..e937ebd97a6295d8436627670c52f91a3528679d 100644
--- a/mace/core/operator.h
+++ b/mace/core/operator.h
@@ -105,7 +105,7 @@ class Operator : public OperatorBase {
                          DataTypeToEnum<T>::v())));
     }
   }
-  virtual bool Run() = 0;
+  virtual bool Run() override = 0;
   ~Operator() noexcept override {}
 };