-prefix = @prefix@
-datarootdir = @datarootdir@
-exec_prefix = @exec_prefix@
-bindir = @bindir@
-datadir0 = @datadir@
-libdir0 = @libdir@
-includedir = @includedir@
-oldincludedir = @oldincludedir@
-mandir = @mandir@
+prefix := @prefix@
+
+# New autoconf (>= 2.60?) make a configure with a --datarootdir=DIR flag.
+# However, in order to support older autoconf's we don't use it.
+# datarootdir is set lower down instead.
+# datarootdir = @datarootdir@
+
+exec_prefix := @exec_prefix@
+bindir := @bindir@
+datadir0 := @datadir@
+libdir0 := @libdir@
+includedir := @includedir@
+oldincludedir := @oldincludedir@
+mandir := @mandir@