http://savannah.gnu.org/bugs/index.php?38273
http://bugs.gentoo.org/455374

--- configure.ac
+++ configure.ac
@@ -394,7 +394,7 @@
 dnl
 dnl Newest automake workaround - needed for multi-language manual pages
 dnl
-AC_SUBST(mkdir_p)
+AC_SUBST(mkdir_p, "${MKDIR_P}")
 
 dnl
 dnl Output configuration files
