diff --git a/src/core/model/deprecated.h b/src/core/model/deprecated.h
index c50a4cbf2..0c38d61b1 100644
--- a/src/core/model/deprecated.h
+++ b/src/core/model/deprecated.h
@@ -60,8 +60,6 @@
 #define NS_DEPRECATED
 #endif
 
-#ifdef NS_DEPRECATED
 #define NS_DEPRECATED_3_31 NS_DEPRECATED
-#endif
 
 #endif /* NS3_DEPRECATED_H */