diff --git a/man2/fork.2 b/man2/fork.2
index 6c61ee662..bd4a1e980 100644
--- a/man2/fork.2
+++ b/man2/fork.2
@@ -222,10 +222,13 @@ the kernel's system-wide limit on the number of processes and threads,
 .IR /proc/sys/kernel/threads-max ,
 was reached (see
 .BR proc (5));
-or the maximum number of PIDs,
+the maximum number of PIDs,
 .IR /proc/sys/kernel/pid_max ,
 was reached (see
-.BR proc (5)).
+.BR proc (5));
+or the PID limit
+.RB ( pids.max )
+imposed by the cgroup "process number" (PIDs) controller was reached.
 .TP
 .B EAGAIN
 The caller is operating under the