diff --git a/configure b/configure
index d5cc892..31f7ae63 100755
--- a/configure
+++ b/configure
@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.in Revision: 1.405 .
+# From configure.in Revision: 1.406 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.53 for python 2.3.
 #
@@ -1354,6 +1354,10 @@
   # of union __?sigval. Reported by Stuart Bishop.
   SunOS/5.6)
     define_xopen_source=no;;
+  # On UnixWare 7, u_short is never defined with _XOPEN_SOURCE,
+  # but used in struct sockaddr.sa_family. Reported by Tim Rice.
+  OpenUNIX/8.0| UnixWare/7.1.[13])
+    define_xopen_source=no;;
 esac
 
 if test $define_xopen_source = yes
diff --git a/configure.in b/configure.in
index fdda1f7..5918bb0 100644
--- a/configure.in
+++ b/configure.in
@@ -129,6 +129,10 @@
   # of union __?sigval. Reported by Stuart Bishop.
   SunOS/5.6)
     define_xopen_source=no;;
+  # On UnixWare 7, u_short is never defined with _XOPEN_SOURCE,
+  # but used in struct sockaddr.sa_family. Reported by Tim Rice.
+  OpenUNIX/8.0| UnixWare/7.1.@<:@13@:>@)
+    define_xopen_source=no;;
 esac
 
 if test $define_xopen_source = yes