diff --git a/man2/add_key.2 b/man2/add_key.2
index 0cf0f910c..a8df6afc9 100644
--- a/man2/add_key.2
+++ b/man2/add_key.2
@@ -189,6 +189,19 @@ The keyring doesn't exist.
 .TP
 .B ENOMEM
 Insufficient memory to create a key.
+.TP
+.B EPERM
+The
+.I type
+started from dot.
+.TP
+.B EPERM
+.I type
+was
+.I """keyring"""
+and the
+.I description
+started from dot.
 .SH VERSIONS
 This system call first appeared in Linux 2.6.10.
 .SH CONFORMING TO