diff --git a/src/ecdsa_impl.h b/src/ecdsa_impl.h
index c9770d6c7d3..c0b812cfa17 100644
--- a/src/ecdsa_impl.h
+++ b/src/ecdsa_impl.h
@@ -260,13 +260,16 @@ static int secp256k1_ecdsa_sig_recover(const secp256k1_ecmult_context *ctx, cons
     secp256k1_gej xj;
     secp256k1_scalar rn, u1, u2;
     secp256k1_gej qj;
+    int r;
 
     if (secp256k1_scalar_is_zero(sigr) || secp256k1_scalar_is_zero(sigs)) {
         return 0;
     }
 
     secp256k1_scalar_get_b32(brx, sigr);
-    VERIFY_CHECK(secp256k1_fe_set_b32(&fx, brx)); /* brx comes from a scalar, so is less than the order; certainly less than p */
+    r = secp256k1_fe_set_b32(&fx, brx);
+    (void)r;
+    VERIFY_CHECK(r); /* brx comes from a scalar, so is less than the order; certainly less than p */
     if (recid & 2) {
         if (secp256k1_fe_cmp_var(&fx, &secp256k1_ecdsa_const_p_minus_order) >= 0) {
             return 0;
diff --git a/src/ecmult_gen_impl.h b/src/ecmult_gen_impl.h
index 2a6c5a05310..b63c4d8662c 100644
--- a/src/ecmult_gen_impl.h
+++ b/src/ecmult_gen_impl.h
@@ -40,8 +40,13 @@ static void secp256k1_ecmult_gen_context_build(secp256k1_ecmult_gen_context *ctx
         static const unsigned char nums_b32[33] = "The scalar for this x is unknown";
         secp256k1_fe nums_x;
         secp256k1_ge nums_ge;
-        VERIFY_CHECK(secp256k1_fe_set_b32(&nums_x, nums_b32));
-        VERIFY_CHECK(secp256k1_ge_set_xo_var(&nums_ge, &nums_x, 0));
+        int r;
+        r = secp256k1_fe_set_b32(&nums_x, nums_b32);
+        (void)r;
+        VERIFY_CHECK(r);
+        r = secp256k1_ge_set_xo_var(&nums_ge, &nums_x, 0);
+        (void)r;
+        VERIFY_CHECK(r);
         secp256k1_gej_set_ge(&nums_gej, &nums_ge);
         /* Add G to make the bits in x uniformly distributed. */
         secp256k1_gej_add_ge_var(&nums_gej, &nums_gej, &secp256k1_ge_const_g, NULL);
diff --git a/src/field_impl.h b/src/field_impl.h
index 551a6243e27..5781167d4e4 100644
--- a/src/field_impl.h
+++ b/src/field_impl.h
@@ -224,6 +224,7 @@ static void secp256k1_fe_inv_var(secp256k1_fe *r, const secp256k1_fe *a) {
         0xFF,0xFF,0xFF,0xFE,0xFF,0xFF,0xFC,0x2F
     };
     unsigned char b[32];
+    int res;
     secp256k1_fe c = *a;
     secp256k1_fe_normalize_var(&c);
     secp256k1_fe_get_b32(b, &c);
@@ -231,7 +232,9 @@ static void secp256k1_fe_inv_var(secp256k1_fe *r, const secp256k1_fe *a) {
     secp256k1_num_set_bin(&m, prime, 32);
     secp256k1_num_mod_inverse(&n, &n, &m);
     secp256k1_num_get_bin(b, 32, &n);
-    VERIFY_CHECK(secp256k1_fe_set_b32(r, b));
+    res = secp256k1_fe_set_b32(r, b);
+    (void)res;
+    VERIFY_CHECK(res);
     /* Verify the result is the (unique) valid inverse using non-GMP code. */
     secp256k1_fe_mul(&c, &c, r);
     secp256k1_fe_add(&c, &negone);
diff --git a/src/num_gmp_impl.h b/src/num_gmp_impl.h
index f43e7a56cc8..7b6a89719ab 100644
--- a/src/num_gmp_impl.h
+++ b/src/num_gmp_impl.h
@@ -70,6 +70,7 @@ static void secp256k1_num_add_abs(secp256k1_num *r, const secp256k1_num *a, cons
 
 static void secp256k1_num_sub_abs(secp256k1_num *r, const secp256k1_num *a, const secp256k1_num *b) {
     mp_limb_t c = mpn_sub(r->data, a->data, a->limbs, b->data, b->limbs);
+    (void)c;
     VERIFY_CHECK(c == 0);
     r->limbs = a->limbs;
     while (r->limbs > 1 && r->data[r->limbs-1]==0) {
@@ -125,6 +126,7 @@ static void secp256k1_num_mod_inverse(secp256k1_num *r, const secp256k1_num *a,
     }
     sn = NUM_LIMBS+1;
     gn = mpn_gcdext(g, r->data, &sn, u, m->limbs, v, m->limbs);
+    (void)gn;
     VERIFY_CHECK(gn == 1);
     VERIFY_CHECK(g[0] == 1);
     r->neg = a->neg ^ m->neg;