--- src/basemath/arith1.c
+++ src/basemath/arith1.c
@@ -3618,7 +3618,7 @@ GEN
 Fp_order(GEN a, GEN o, GEN p) {
   if (lgefint(p) == 3 && (!o || typ(o) == t_INT))
   {
-    ulong pp = p[2], oo = (o && lgefint(o)==3)? o[2]: pp-1;
+    ulong pp = p[2], oo = (o && lgefint(o)==3)? (ulong)(o[2]): pp-1;
     return utoi( Fl_order(umodiu(a, pp), oo, pp) );
   }
   return gen_order(a, o, (void*)p, &Fp_star);
@@ -4106,7 +4106,7 @@ Fl_log_Fp(ulong a, ulong g, ulong ord, u
 {
   pari_sp av = avma;
   GEN r = Fp_log(utoi(a),utoi(g),utoi(ord),utoi(p));
-  ulong z = typ(r)==t_INT ? itou(r): ~0L;
+  ulong z = (typ(r)==t_INT) ? itou(r): ~0UL;
   avma = av; return z;
 }
 
--- src/basemath/base4.c
+++ src/basemath/base4.c
@@ -504,7 +504,7 @@ idealHNF_Z_factor_i(GEN x, GEN f0, GEN *
   for (i = 1; i < l; i++)
   {
     GEN p = gel(P,i);
-    vZ[i] = f0? Z_pval(xZ, p): itou(gel(E,i));
+    vZ[i] = f0? Z_pval(xZ, p): itos(gel(E,i));
     vN[i] = idealHNF_norm_pval(x,p, vZ[i]);
   }
   return P;
--- src/basemath/char.c
+++ src/basemath/char.c
@@ -407,7 +407,7 @@ zv_cyc_minimize(GEN cyc, GEN g, GEN copr
     gk = vecmoduu(gk, cyc);
     if (vecsmall_lexcmp(gk, best) < 0) { best = gk; bestk = k; }
   }
-  avma = av; return bestk == 1? k0: Fl_mul(k0, bestk, o);
+  avma = av; return bestk == 1? k0: (long)Fl_mul(k0, bestk, o);
 }
 /* g of order o in abelian group G attached to cyc. Is g a minimal generator
  * [wrt lex order] of the cyclic subgroup it generates;
--- src/basemath/hyperell.c
+++ src/basemath/hyperell.c
@@ -683,7 +683,7 @@ Flx_genus2charpoly_naive(GEN H, ulong p)
     {
       GEN r2 = gel(V, n+1);
       c += uel(r2,2) ?
-        (uel(r2,1) ? k[1+Fl2_norm_pre(r2, D, p, pi)]: e)
+        (uel(r2,1) ? (ulong)(k[1+Fl2_norm_pre(r2, D, p, pi)]): e)
          : !!uel(r2,1);
       if (i == p-1) break;
       V = Fl2V_next(V, p);
--- src/basemath/mftrace.c
+++ src/basemath/mftrace.c
@@ -10967,7 +10967,7 @@ mfslashexpansion(GEN mf, GEN f, GEN ga,
     long CD = (C * D) % N, BC = (B * C) % F;
     GEN CV, t;
     /* weight of f * Theta in 1/2-integral weight */
-    k = typ(gk) == t_INT? itou(gk): MF_get_r(mf)+1;
+    k = (typ(gk) == t_INT)? itos(gk): MF_get_r(mf)+1;
     CV = odd(k) ? powuu(N, k - 1) : powuu(N, k >> 1);
     deg = ulcm(ulcm(ord, N/ugcd(N,CD)), F/ugcd(F,BC));
     V = bestapprnf2(V, deg, CV, prec);
--- src/basemath/nffactor.c
+++ src/basemath/nffactor.c
@@ -2049,7 +2049,7 @@ guess_roots(GEN nf)
     /* the gcd of the p^f - 1 is p^(gcd of the f's) - 1 */
     for (i = 1; i <= nfdegree; i++)
       if (F[i]) {
-        gcdf = gcdf? ugcd(gcdf, i): i;
+        gcdf = gcdf? (long)ugcd(gcdf, i): i;
         if (gcdf == 1) break;
       }
     pf_1 = subiu(powuu(p, gcdf), 1);
--- src/language/sumiter.c
+++ src/language/sumiter.c
@@ -269,14 +269,14 @@ forfactored(GEN a, GEN b, GEN code)
   sb = signe(b);
   if (sa < 0)
   {
-    stop = forfactoredneg((sb < 0)? b[2]: 1UL, itou(a), code);
+    stop = forfactoredneg((sb < 0)? (ulong)b[2]: 1UL, itou(a), code);
     if (!stop && sb >= 0) stop = eval0(code);
     if (!stop && sb > 0) forfactoredpos(1UL, b[2], code);
   }
   else
   {
     if (!sa) stop = eval0(code);
-    if (!stop && sb) forfactoredpos(sa? a[2]: 1UL, itou(b), code);
+    if (!stop && sb) forfactoredpos(sa? (ulong)a[2]: 1UL, itou(b), code);
   }
   pop_lex(1); avma = av;
 }