diff --git a/include/sal.h b/include/sal.h
index c69f7f9840c..29746c3a038 100644
--- a/include/sal.h
+++ b/include/sal.h
@@ -34,6 +34,7 @@
 #define _Deref_post_valid_
 #define _Deref_post_z_
 #define _Deref_prepost_opt_z_
+#define _Deref_ret_z_
 
 #define _Field_range_(min, max)