--- a/configure.ac
+++ b/configure.ac
@@ -397,12 +397,14 @@ AC_SUBST(rl_inc)
 dnl # ----------------------
 dnl # HANDLE THE MPI LIBRARY
 dnl # ----------------------
+mpi_use=""
 AC_MSG_CHECKING([whether you want MPI])
-AC_ARG_ENABLE(mpi,
-    [  --enable-mpi            enable MPI layer [[default=no]]],
-    [ mpi_use="yes" ],
-    [ mpi_use=""    ]
-)
+AC_ARG_ENABLE([mpi],
+    AS_HELP_STRING([--enable-mpi            enable MPI layer [[default=no]]]))
+
+AS_IF([test "x$enable_mpi" = "xyes"], [
+    mpi_use="yes"
+])
 mpi_lib="";
 mpi_inc="";
 if test -z "${mpi_use}"; then