--- Libc/Libc-391.2.9/pthreads/pthread_cleanup_pop.3
+++ Libc/Libc-583/pthreads/pthread_cleanup_pop.3
@@ -40,14 +40,18 @@
 .Sh DESCRIPTION
 The
 .Fn pthread_cleanup_pop
-function pops the top cleanup routine off of the current threads cleanup
-routine stack, and, if
+function pops the top cleanup routine off
+of the current thread's cleanup routine stack and, if
 .Fa execute
 is non-zero, it will execute the function.
-If there is no cleanup routine
-then
+If there is no cleanup routine,
 .Fn pthread_cleanup_pop
 does nothing.
+.Pp
+.Fn pthread_cleanup_pop
+must be paired with a corresponding
+.Xr pthread_cleanup_push 3
+in the same lexical scope.
 .Sh RETURN VALUES
 .Fn pthread_cleanup_pop
 does not return any value.