--- a/interfaces/Prolog/Ciao/ciao_cfli.hh
+++ b/interfaces/Prolog/Ciao/ciao_cfli.hh
@@ -296,7 +296,7 @@ Prolog_get_atom_name(Prolog_term_ref t,
   The behavior is undefined if \p t is not a Prolog compound term.
 */
 inline int
-Prolog_get_compound_name_arity(Prolog_term_ref t, Prolog_atom* ap, int* ip) {
+Prolog_get_compound_name_arity(Prolog_term_ref t, Prolog_atom* ap, size_t* ip) {
   assert(Prolog_is_compound(t));
   *ap = ciao_structure_name(t);
   *ip = ciao_structure_arity(t);
--- a/interfaces/Prolog/GNU/gprolog_cfli.hh
+++ b/interfaces/Prolog/GNU/gprolog_cfli.hh
@@ -420,9 +420,11 @@ Prolog_get_atom_name(Prolog_term_ref t,
   The behavior is undefined if \p t is not a Prolog compound term.
 */
 inline int
-Prolog_get_compound_name_arity(Prolog_term_ref t, Prolog_atom* ap, int* ip) {
+Prolog_get_compound_name_arity(Prolog_term_ref t, Prolog_atom* ap, size_t* ip) {
+  int i;
   assert(Prolog_is_compound(t));
-  Rd_Compound_Check(t, ap, ip);
+  Rd_Compound_Check(t, ap, &i);
+  *ip = (size_t)i;
   return 1;
 }
 
--- a/interfaces/Prolog/ppl_interface_generator_prolog_cc_code.m4
+++ b/interfaces/Prolog/ppl_interface_generator_prolog_cc_code.m4
@@ -1934,7 +1934,7 @@ m4_define(`ppl_@CLASS@_map_space_dimensi
     while (Prolog_is_cons(t_pfunc)) {
       Prolog_get_cons(t_pfunc, t_pair, t_pfunc);
       Prolog_atom functor;
-      int arity;
+      size_t arity;
       Prolog_get_compound_name_arity(t_pair, &functor, &arity);
       if (arity != 2 || functor != a_minus)
         return PROLOG_FAILURE;
--- a/interfaces/Prolog/ppl_prolog_common.cc
+++ b/interfaces/Prolog/ppl_prolog_common.cc
@@ -937,7 +937,7 @@ build_linear_expression(Prolog_term_ref
     return Linear_Expression(integer_term_to_Coefficient(t));
   else if (Prolog_is_compound(t)) {
     Prolog_atom functor;
-    int arity;
+    size_t arity;
     Prolog_get_compound_name_arity(t, &functor, &arity);
     switch (arity) {
     case 1:
@@ -1000,7 +1000,7 @@ Constraint
 build_constraint(Prolog_term_ref t, const char* where) {
   if (Prolog_is_compound(t)) {
     Prolog_atom functor;
-    int arity;
+    size_t arity;
     Prolog_get_compound_name_arity(t, &functor, &arity);
     if (arity == 2) {
       Prolog_term_ref arg1 = Prolog_new_term_ref();
@@ -1073,7 +1073,7 @@ Congruence
 build_congruence(Prolog_term_ref t, const char* where) {
   if (Prolog_is_compound(t)) {
     Prolog_atom functor;
-    int arity;
+    size_t arity;
     Prolog_get_compound_name_arity(t, &functor, &arity);
     if (arity == 2) {
       Prolog_term_ref arg1 = Prolog_new_term_ref();
@@ -1084,7 +1084,7 @@ build_congruence(Prolog_term_ref t, cons
         // /
         if (Prolog_is_integer(arg2)) {
           Prolog_atom functor1;
-          int arity1;
+          size_t arity1;
           Prolog_get_compound_name_arity(arg1, &functor1, &arity1);
           if (arity1 == 2) {
             if (functor1 == a_is_congruent_to) {
@@ -1137,7 +1137,7 @@ Generator
 build_generator(Prolog_term_ref t, const char* where) {
   if (Prolog_is_compound(t)) {
     Prolog_atom functor;
-    int arity;
+    size_t arity;
     Prolog_get_compound_name_arity(t, &functor, &arity);
     if (arity == 1) {
       Prolog_term_ref arg = Prolog_new_term_ref();
@@ -1174,7 +1174,7 @@ Grid_Generator
 build_grid_generator(Prolog_term_ref t, const char* where) {
   if (Prolog_is_compound(t)) {
     Prolog_atom functor;
-    int arity;
+    size_t arity;
     Prolog_get_compound_name_arity(t, &functor, &arity);
     if (arity == 1) {
       Prolog_term_ref arg = Prolog_new_term_ref();
@@ -1406,7 +1406,7 @@ Variable
 term_to_Variable(Prolog_term_ref t, const char* where) {
   if (Prolog_is_compound(t)) {
     Prolog_atom functor;
-    int arity;
+    size_t arity;
     Prolog_get_compound_name_arity(t, &functor, &arity);
     if (functor == a_dollar_VAR && arity == 1) {
       Prolog_term_ref arg = Prolog_new_term_ref();
@@ -1554,7 +1554,7 @@ term_to_boundary(Prolog_term_ref t_b, Bo
     return false;
 
   Prolog_atom functor;
-  int arity;
+  size_t arity;
 
   Prolog_get_compound_name_arity(t_b, &functor, &arity);
   // A boundary term is either of the form c(Limit) or o(Limit).
--- a/interfaces/Prolog/SICStus/sicstus_cfli.h
+++ b/interfaces/Prolog/SICStus/sicstus_cfli.h
@@ -134,7 +134,7 @@ Prolog_get_atom_name(Prolog_term_ref t,
 
 PCFLI_DECLSPEC int
 Prolog_get_compound_name_arity(Prolog_term_ref t,
-                               Prolog_atom& name, int& arity);
+                               Prolog_atom& name, size_t& arity);
 
 PCFLI_DECLSPEC int
 Prolog_get_arg(int i, Prolog_term_ref t, Prolog_term_ref a);
--- a/interfaces/Prolog/SICStus/sicstus_cfli.ic
+++ b/interfaces/Prolog/SICStus/sicstus_cfli.ic
@@ -262,9 +262,12 @@ Prolog_get_atom_name(Prolog_term_ref t,
   The behavior is undefined if \p t is not a Prolog compound term.
 */
 PCFLI_EXTERN_INLINE int
-Prolog_get_compound_name_arity(Prolog_term_ref t, Prolog_atom* ap, int* ip) {
+Prolog_get_compound_name_arity(Prolog_term_ref t, Prolog_atom* ap, size_t* ip) {
+  int i, ret;
   assert(Prolog_is_compound(t));
-  return SP_get_functor(t, ap, ip);
+  ret = SP_get_functor(t, ap, &i);
+  *ip = i;
+  return ret;
 }
 
 /*!
--- a/interfaces/Prolog/SWI/swi_cfli.hh
+++ b/interfaces/Prolog/SWI/swi_cfli.hh
@@ -346,7 +346,7 @@ Prolog_get_atom_name(Prolog_term_ref t,
   The behavior is undefined if \p t is not a Prolog compound term.
 */
 inline int
-Prolog_get_compound_name_arity(Prolog_term_ref t, Prolog_atom* ap, int* ip) {
+Prolog_get_compound_name_arity(Prolog_term_ref t, Prolog_atom* ap, size_t* ip) {
   assert(Prolog_is_compound(t));
   return PL_get_name_arity(t, ap, ip);
 }
--- a/interfaces/Prolog/XSB/xsb_cfli.hh
+++ b/interfaces/Prolog/XSB/xsb_cfli.hh
@@ -314,10 +314,10 @@ Prolog_get_atom_name(Prolog_term_ref t,
   The behavior is undefined if \p t is not a Prolog compound term.
 */
 inline int
-Prolog_get_compound_name_arity(Prolog_term_ref t, Prolog_atom* ap, int* ip) {
+Prolog_get_compound_name_arity(Prolog_term_ref t, Prolog_atom* ap, size_t* ip) {
   assert(Prolog_is_compound(t));
   *ap = p2c_functor(t);
-  *ip = p2c_arity(t);
+  *ip = (size_t)p2c_arity(t);
   return 1;
 }
 
--- a/interfaces/Prolog/YAP/yap_cfli.hh
+++ b/interfaces/Prolog/YAP/yap_cfli.hh
@@ -313,7 +313,7 @@ Prolog_get_atom_name(Prolog_term_ref t,
   The behavior is undefined if \p t is not a Prolog compound term.
 */
 inline int
-Prolog_get_compound_name_arity(Prolog_term_ref t, Prolog_atom* ap, int* ip) {
+Prolog_get_compound_name_arity(Prolog_term_ref t, Prolog_atom* ap, size_t* ip) {
   assert(Prolog_is_compound(t));
   YAP_Functor f = YAP_FunctorOfTerm(t);
   *ap = YAP_NameOfFunctor(f);
--- a/m4/ac_check_swi_prolog.m4
+++ b/m4/ac_check_swi_prolog.m4
@@ -45,11 +45,11 @@ then
 fi
 if test x$swi_prolog != x
 then
-  swi_prolog_base=`$swi_prolog -dump-runtime-variables | grep PLBASE= | sed 's/PLBASE="\([[a-z]]:\)\{0,1\}\(.*\)";.*/\2/'`
-  swi_prolog_version=`$swi_prolog -dump-runtime-variables | grep PLVERSION= | sed 's/PLVERSION="\(.*\)";.*/\1/'`
-  swi_prolog_arch=`$swi_prolog -dump-runtime-variables | grep PLARCH= | sed 's/PLARCH="\(.*\)";.*/\1/'`
-  swi_prolog_libs=`$swi_prolog -dump-runtime-variables | grep PLLIBS= | sed 's/PLLIBS="\(.*\)";.*/\1/'`
-  swi_prolog_lib=`$swi_prolog -dump-runtime-variables | grep PLLIB= | sed 's/PLLIB="\(.*\)";.*/\1/'`
+  swi_prolog_base=`$swi_prolog --dump-runtime-variables | grep PLBASE= | sed 's/PLBASE="\([[a-z]]:\)\{0,1\}\(.*\)";.*/\2/'`
+  swi_prolog_version=`$swi_prolog --dump-runtime-variables | grep PLVERSION= | sed 's/PLVERSION="\(.*\)";.*/\1/'`
+  swi_prolog_arch=`$swi_prolog --dump-runtime-variables | grep PLARCH= | sed 's/PLARCH="\(.*\)";.*/\1/'`
+  swi_prolog_libs=`$swi_prolog --dump-runtime-variables | grep PLLIBS= | sed 's/PLLIBS="\(.*\)";.*/\1/'`
+  swi_prolog_lib=`$swi_prolog --dump-runtime-variables | grep PLLIB= | sed 's/PLLIB="\(.*\)";.*/\1/'`
 
   dnl Additional version checks could be inserted here, if necessary.