diff --git a/configure b/configure
index 5bbccce..b96349a 100755
--- a/configure
+++ b/configure
@@ -1553,7 +1553,7 @@
   # On OpenBSD, select(2) is not available if _XOPEN_SOURCE is defined,
   # even though select is a POSIX function. Reported by J. Ribbens.
   # Reconfirmed for OpenBSD 3.3 by Zachary Hamm, for 3.4 by Jason Ish.
-  OpenBSD/2.* | OpenBSD/3.[0123456789])
+  OpenBSD/2.* | OpenBSD/3.[0123456789] | OpenBSD/4.[0])
     define_xopen_source=no;;
   # On Solaris 2.6, sys/wait.h is inconsistent in the usage
   # of union __?sigval. Reported by Stuart Bishop.