diff --git a/man2/kcmp.2 b/man2/kcmp.2
index b13cc437c..d834a17bf 100644
--- a/man2/kcmp.2
+++ b/man2/kcmp.2
@@ -187,7 +187,12 @@ is invalid.
 Insufficient permission to inspect process resources.
 The
 .B CAP_SYS_PTRACE
-capability is required to inspect processes that you do not own.
+capability is required to inspect processes that you do not own. Other
+limitations on ptrace apply, such as
+.BR CONFIG_SECURITY_YAMA ,
+which when /proc/sys/kernel/yama/ptrace_scope is 2 (the default) limits
+.BR kcmp()
+to child processes.
 .TP
 .B ESRCH
 Process