diff --git a/man2/prctl.2 b/man2/prctl.2
index 314c09cd1..12d0b94a8 100644
--- a/man2/prctl.2
+++ b/man2/prctl.2
@@ -66,6 +66,11 @@ prctl \- operations on a process or thread
 manipulates various aspects of the behavior
 of the calling thread or process.
 .PP
+Note that careless use of
+.BR prctl ()
+can confuse the userspace run-time environment,
+so these operations should be used with care (if at all).
+.PP
 .BR prctl ()
 is called with a first argument describing what to do
 (with values defined in \fI<linux/prctl.h>\fP), and further