diff --git a/ev.pod b/ev.pod
index 606c748..429fe58 100644
--- a/ev.pod
+++ b/ev.pod
@@ -413,9 +413,10 @@ make libev check for a fork in each iteration by enabling this flag.
 This works by calling C<getpid ()> on every iteration of the loop,
 and thus this might slow down your event loop if you do a lot of loop
 iterations and little real work, but is usually not noticeable (on my
-GNU/Linux system for example, C<getpid> is actually a simple 5-insn sequence
-without a system call and thus I<very> fast, but my GNU/Linux system also has
-C<pthread_atfork> which is even faster).
+GNU/Linux system for example, C<getpid> is actually a simple 5-insn
+sequence without a system call and thus I<very> fast, but my GNU/Linux
+system also has C<pthread_atfork> which is even faster). (Update: glibc
+versions 2.25 apparently removed the C<getpid> optimisation again).
 
 The big advantage of this flag is that you can forget about fork (and
 forget about forgetting to tell libev about forking, although you still