diff --git a/configure.in b/configure.ac
similarity index 99%
rename from configure.in
rename to configure.ac
index 67d6ac26..c7f815e6 100644
--- a/configure.in
+++ b/configure.ac
@@ -1,5 +1,5 @@
-dnl Process this file with autoconf to produce a configure script.
-dnl $Id$
+# Process this file with autoconf to produce a configure script.
+# $Id$
 
 AC_INIT(lib/mbselib.h)
 AM_CONFIG_HEADER(config.h)