diff --git a/include/dsn/utility/defer.h b/include/dsn/utility/defer.h
index 4e3fe3f5ba..83c34e32b7 100644
--- a/include/dsn/utility/defer.h
+++ b/include/dsn/utility/defer.h
@@ -24,6 +24,8 @@
  * THE SOFTWARE.
  */
 
+#pragma once
+
 #include <utility>
 
 namespace dsn {