diff --git a/man2/sigprocmask.2 b/man2/sigprocmask.2
index c02e8bc92..24c06c944 100644
--- a/man2/sigprocmask.2
+++ b/man2/sigprocmask.2
@@ -110,7 +110,7 @@ The value specified in
 .I how
 was invalid.
 .SH CONFORMING TO
-POSIX.1-2001.
+POSIX.1-2001, POSIX.1-2008.
 .SH NOTES
 It is not possible to block
 .BR SIGKILL " or " SIGSTOP .