diff --git a/configure b/configure
index 4bd4740..7fc3bfd 100755
--- a/configure
+++ b/configure
@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.in Revision: 1.333 .
+# From configure.in Revision: 1.334 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.53.
 #
@@ -1225,6 +1225,23 @@
 
 SOVERSION=1.0
 
+# The later defininition of _XOPEN_SOURCE disables certain features
+# on Linux, so we need _GNU_SOURCE to re-enable them (makedev, tm_zone).
+
+cat >>confdefs.h <<\_ACEOF
+#define _GNU_SOURCE 1
+_ACEOF
+
+
+# The definition of _GNU_SOURCE potentially causes a change of the value
+# of _XOPEN_SOURCE. So define it only conditionally.
+
+
+cat >>confdefs.h <<\_ACEOF
+#define _XOPEN_SOURCE 500
+_ACEOF
+
+
 # Arguments passed to configure.
 
 CONFIG_ARGS="$ac_configure_args"