diff --git a/m4/buildsys.m4 b/build-aux/m4/buildsys.m4
similarity index 100%
rename from m4/buildsys.m4
rename to build-aux/m4/buildsys.m4
diff --git a/configure.ac b/configure.ac
index 95f5b5c..8b38f50 100644
--- a/configure.ac
+++ b/configure.ac
@@ -9,10 +9,18 @@ dnl
 
 dnl Specify name, version and contact e-mail of the package.
 AC_INIT(name, version, e-mail)
-BUILDSYS_INIT
-
 dnl Specifies where your sources are.
 AC_CONFIG_SRCDIR(src)
+AC_CONFIG_AUX_DIR(build-aux)
+AC_CONFIG_MACRO_DIR(build-aux/m4)
+
+for i in configure.ac build-aux/m4/*; do
+	AS_IF([test $i -nt configure], [
+		AC_MSG_ERROR([$i is newer than configure! Run ./autogen.sh!])
+	])
+done
+
+BUILDSYS_INIT
 
 dnl If your package uses C, you want a C compiler and a C preprocessor
 AC_PROG_CC
@@ -26,7 +34,9 @@ dnl AC_PROG_LN_S
 dnl If you want to build static libraries (for example build part of your
 dnl project as a static library and link it to the final program later so you
 dnl can easier split your program into multiple directories), you need to
-dnl uncomment the following line.
+dnl uncomment the following line. This is also needed if you build .a files in
+dnl subdirectories that you then link into a shared library or application in 
+dnl the end.
 dnl AC_PATH_TOOL(AR, ar)
 
 dnl If you want to build a shared library, you need to call BUILDSYS_SHARED_LIB.
@@ -46,8 +56,5 @@ dnl If you use extra variables, comment the line above and uncomment the line
 dnl below.
 dnl AC_CONFIG_FILES([buildsys.mk extra.mk])
 
-dnl Generate config.h if we did some defines.
-dnl AC_CONFIG_HEADERS(config.h)
-
 dnl Write out configure script
 AC_OUTPUT