Disable _XOPEN_SOURCE on NetBSD 1.x.
diff --git a/Misc/NEWS b/Misc/NEWS
index 9b8fc27..2d790f2 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -201,6 +201,8 @@
 Build
 -----
 
+- Disable _XOPEN_SOURCE on NetBSD 1.x.
+
 - Bug #1578513: Cross compilation was broken by a change to configure.
   Repair so that it's back to how it was in 2.4.3.