diff --git a/config/bb_enable_doxygen.m4 b/config/bb_enable_doxygen.m4
index b521fdd..0757544 100644
--- a/config/bb_enable_doxygen.m4
+++ b/config/bb_enable_doxygen.m4
@@ -1,6 +1,6 @@
-AC_DEFUN(BB_ENABLE_DOXYGEN,
+AC_DEFUN([BB_ENABLE_DOXYGEN],
 [
-AC_ARG_ENABLE(doxygen, [  --enable-doxygen        enable documentation generation with doxygen (auto)])
+AC_ARG_ENABLE(doxygen, AS_HELP_STRING([--enable-doxygen],[enable documentation generation with doxygen (auto)]))
 if test "x$enable_doxygen" = xno; then
         enable_doc=no
 else