diff --git a/autogen.sh b/autogen.sh
index dd5b91ad2..37db90e0e 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -2,22 +2,6 @@
 # Run this to generate all the initial makefiles, etc.
 set -e
 
-PACKAGE=cairo
-
-LIBTOOLIZE=${LIBTOOLIZE-libtoolize}
-LIBTOOLIZE_FLAGS="--copy --force"
-AUTOHEADER=${AUTOHEADER-autoheader}
-AUTOMAKE_FLAGS="--add-missing --foreign"
-AUTOCONF=${AUTOCONF-autoconf}
-
-# automake 1.9 requires autoconf ???
-# automake 1.8 requires autoconf 2.58
-# automake 1.7 requires autoconf 2.54
-automake_min_vers=1.9
-aclocal_min_vers=$automake_min_vers
-autoconf_min_vers=2.54
-libtoolize_min_vers=1.4
-
 # The awk-based string->number conversion we use needs a C locale to work 
 # as expected. Setting LC_ALL overrides whether the user set LC_ALL,
 # LC_NUMERIC, or LANG.
@@ -34,6 +18,32 @@ ORIGDIR=`pwd`
 
 cd $srcdir
 
+PACKAGE=cairo
+
+LIBTOOLIZE=${LIBTOOLIZE-libtoolize}
+LIBTOOLIZE_FLAGS="--copy --force"
+AUTOHEADER=${AUTOHEADER-autoheader}
+AUTOMAKE_FLAGS="--add-missing --foreign"
+AUTOCONF=${AUTOCONF-autoconf}
+
+CONFIGURE_IN=
+test -f configure.in && CONFIGURE_IN=configure.in
+test -f configure.ac && CONFIGURE_IN=configure.ac
+
+if test "X$CONFIGURE_IN" = X; then
+  echo "$ARGV0: ERROR: No $srcdir/configure.in or $srcdir/configure.ac found."
+  exit 1
+fi
+
+extract_version() {
+	grep "^ *$1" $CONFIGURE_IN | sed 's/.*(\[\?\([^])]\+\)]\?).*/\1/'
+}
+
+autoconf_min_vers=`extract_version AC_PREREQ`
+automake_min_vers=`extract_version AM_INIT_AUTOMAKE`
+libtoolize_min_vers=`extract_version AC_PROG_LIBTOOL`
+aclocal_min_vers=$automake_min_vers
+
 if ($AUTOCONF --version) < /dev/null > /dev/null 2>&1 ; then
     if ($AUTOCONF --version | head -n 1 | awk 'NR==1 { if( $(NF) >= '$autoconf_min_vers') \
 			       exit 1; exit 0; }');
diff --git a/configure.in b/configure.in
index 90530f858..966a5caec 100644
--- a/configure.in
+++ b/configure.in
@@ -1,8 +1,8 @@
 AC_PREREQ(2.54)
 
-# cairo package version number, (as distinct from shared library version)
-# An odd micro number indicates in-progress development, (eg. from git/cvs)
-# An even micro number indicates a released version.
+dnl cairo package version number, (as distinct from shared library version)
+dnl An odd micro number indicates in-progress development, (eg. from git/cvs)
+dnl An even micro number indicates a released version.
 m4_define(cairo_version_major, 1)
 m4_define(cairo_version_minor, 2)
 m4_define(cairo_version_micro, 5)
@@ -12,6 +12,9 @@ AC_INIT([cairo],
       [http://bugs.freedesktop.org/enter_bug.cgi?product=cairo])
 AC_CONFIG_SRCDIR(src/cairo.h)
 AC_CONFIG_HEADERS(config.h)
+
+dnl automake 1.8 requires autoconf 2.58
+dnl automake 1.7 requires autoconf 2.54
 AM_INIT_AUTOMAKE([1.9])
 
 dnl ===========================================================================
@@ -49,7 +52,7 @@ AM_MAINTAINER_MODE
 
 AC_PROG_CC
 AC_PROG_CPP
-AM_PROG_LIBTOOL
+AC_PROG_LIBTOOL dnl required version (1.4) DON'T REMOVE!
 AC_STDC_HEADERS
 AC_C_BIGENDIAN
 
@@ -57,10 +60,10 @@ dnl ===========================================================================
 dnl === Local macros
 dnl ===========================================================================
 
-# _CHECK_FUNCS_WITH_FLAGS(FUNCTION..., CFLAGS, LIBS 
-#                         [, ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND]])
-# Like AC_CHECK_FUNCS but with additional CFLAGS and LIBS
-# --------------------------------------------------------------------
+dnl _CHECK_FUNCS_WITH_FLAGS(FUNCTION..., CFLAGS, LIBS
+dnl                         [, ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND]])
+dnl Like AC_CHECK_FUNCS but with additional CFLAGS and LIBS
+dnl --------------------------------------------------------------------
 AC_DEFUN([_CHECK_FUNCS_WITH_FLAGS],
 [ 
   save_cflags="$CFLAGS"