diff --git a/C/arith1.c b/C/arith1.c
index e5a202bb7..42f45ee15 100644
--- a/C/arith1.c
+++ b/C/arith1.c
@@ -249,7 +249,7 @@ p_unot(Term t E_ARGS)
 #ifdef USE_GMP
   case big_int_e:
     {
-      mpz_t new;
+      MP_INT *new = TMP_BIG();
 
       mpz_init_set(new, Yap_BigIntOfTerm(t));
       mpz_com(new, new);
@@ -1579,7 +1579,7 @@ p_integer(Term t E_ARGS)
     RINT((Int) dbl);
   } else {
 #ifdef USE_GMP
-    mpz_t new;
+    MP_INT *new = TMP_BIG();
 
     mpz_init_set_d(new, dbl);
     RBIG(new);
diff --git a/changes-5.1.html b/changes-5.1.html
index e8e77591c..a0ac5c848 100644
--- a/changes-5.1.html
+++ b/changes-5.1.html
@@ -16,10 +16,13 @@
 
 <h2>Yap-5.1.0:</h2>
 <ul>
-<li> FIXED: YENV may be an HW register (breaks some tabling code) </li>
+<li> FIXED: don't pass a pointer to a mpz_t.</li>
+<li> FIXED: YENV may be an HW register ('d break some tabling code)
+  (Remko Troncon) </li>
 <li> FIXED: All YAAM instructions are now brackedted, so Op introduced an { and EndOp intr
 oduces an }. This is because Ricardo assumes that. </li>
-<li> Fix attvars when COROUTING is undefined. </li>
+<li> FIXED: compile attvars when COROUTING is undefined. </li>
+<li> FIXED: compiler warnings due to c-interface changes</li>.
 <li> FIXED: scanner would convert LONG_MIN to bigint, but it can be
   represent as a LONG; fixed by using mpz_fits_slong_p (Roberto Bagnara). </li>
 <li> FIXED: indexing cut should stop looking after a cut!!!! (Paulo Moura).