diff --git a/man2/setuid.2 b/man2/setuid.2
index 699ac2f53..14b157aec 100644
--- a/man2/setuid.2
+++ b/man2/setuid.2
@@ -75,6 +75,13 @@ is set appropriately.
 .SH ERRORS
 .TP
 .B EAGAIN
+The call would change the caller's real UID (i.e.,
+.I uid
+does not match the caller's real UID),
+but there was a temporary failure allocating the
+necessary kernel data structures.
+.TP
+.B EAGAIN
 .I uid
 does not match the real user ID of the caller and this call would
 bring the number of processes belonging to the real user ID