diff -up ppl-1.1/interfaces/Prolog/GNU/gprolog_efli.hh.orig ppl-1.1/interfaces/Prolog/GNU/gprolog_efli.hh
--- ppl-1.1/interfaces/Prolog/GNU/gprolog_efli.hh.orig	2014-04-29 17:25:21.639273848 -0300
+++ ppl-1.1/interfaces/Prolog/GNU/gprolog_efli.hh	2014-04-29 17:25:30.757274198 -0300
@@ -45,14 +45,14 @@ extern bool Prolog_has_unbounded_integer
   integer value representable by a Prolog integer.
   Holds zero otherwise.
 */
-extern long Prolog_min_integer;
+extern PlLong Prolog_min_integer;
 
 /*!
   If \p Prolog_has_unbounded_integers is false, holds the maximum
   integer value representable by a Prolog integer.
   Holds zero otherwise.
 */
-extern long Prolog_max_integer;
+extern PlLong Prolog_max_integer;
 
 /*!
   Performs system-dependent initialization.