+dnl ------------------
+dnl By default we put backend executables in $(libexecdir)/nmh and
+dnl configuration files in $(sysconfdir)/nmh, but let a user override
+dnl these choices by supplying these variables
+dnl ------------------
+
+AC_ARG_VAR([nmhlibexecdir], [The installation directory for backend programs
+used by nmh. Defaults to $(libexecdir)/nmh.])
+AS_IF([test -z ${nmhlibexecdir+x}], [nmhlibexecdir='${libexecdir}/nmh'])
+
+AC_ARG_VAR([nmhetcdir], [The installation directory for configuration files
+used by nmh. Defaults to $(sysconfdir)/nmh.])
+AS_IF([test -z ${nmhetcdir+x}], [nmhetcdir='${sysconfdir}/nmh'])
+