diff --git a/src/core/model/deprecated.h b/src/core/model/deprecated.h
index 7401151ef..36a787d6e 100644
--- a/src/core/model/deprecated.h
+++ b/src/core/model/deprecated.h
@@ -74,6 +74,13 @@
  */
 #define NS_DEPRECATED(msg) [[deprecated(msg)]]
 
+/**
+ * \ingroup core
+ * \def NS_DEPRECATED_3_40
+ * Tag for things deprecated in version ns-3.40.
+ */
+#define NS_DEPRECATED_3_40(msg) NS_DEPRECATED(msg)
+
 /**
  * \ingroup core
  * \def NS_DEPRECATED_3_39