diff --git a/man2/request_key.2 b/man2/request_key.2
index ae0d5179f..285c944e6 100644
--- a/man2/request_key.2
+++ b/man2/request_key.2
@@ -161,6 +161,18 @@ it to the keyring.
 The request was interrupted by a signal; see
 .BR signal (7).
 .TP
+.B EINVAL
+The size of the string (including the terminating null byte) specified in
+.I type
+or
+.I description
+exceeded the limit (32 bytes and 4096 bytes respectively).
+.TP
+.B EINVAL
+The size of the string (including the terminating null byte) specified in
+.I callout_info
+exceeded the system page size.
+.TP
 .B EKEYEXPIRED
 An expired key was found, but no replacement could be obtained.
 .TP