diff --git a/man2/bdflush.2 b/man2/bdflush.2
index 9c2016e50..7101efb13 100644
--- a/man2/bdflush.2
+++ b/man2/bdflush.2
@@ -112,6 +112,8 @@ or to write an invalid value to a parameter.
 Caller does not have the
 .B CAP_SYS_ADMIN
 capability.
+.SH
+Since version 2.23, glibc no longer supports this obsolete system call.
 .SH CONFORMING TO
 .BR bdflush ()
 is Linux-specific and should not be used in programs