diff --git a/src/crypto/crypto_wolfssl.c b/src/crypto/crypto_wolfssl.c
index c260d4ed0..11f7b361a 100644
--- a/src/crypto/crypto_wolfssl.c
+++ b/src/crypto/crypto_wolfssl.c
@@ -1586,18 +1586,18 @@ int crypto_ec_point_solve_y_coord(struct crypto_ec *e,
 				  struct crypto_ec_point *p,
 				  const struct crypto_bignum *x, int y_bit)
 {
-	byte buf[MAX_ECC_BYTES + 1];
+	byte buf[1 + 2 * MAX_ECC_BYTES];
 	int ret;
 	int prime_len = crypto_ec_prime_len(e);
 
 	if (TEST_FAIL())
 		return -1;
 
-	buf[0] = 0x2 + (byte) y_bit;
+	buf[0] = y_bit ? ECC_POINT_COMP_ODD : ECC_POINT_COMP_EVEN;
 	ret = crypto_bignum_to_bin(x, buf + 1, prime_len, prime_len);
 	if (ret <= 0)
 		return -1;
-	ret = wc_ecc_import_point_der(buf, ret + 1, e->key.idx,
+	ret = wc_ecc_import_point_der(buf, 1 + 2 * ret, e->key.idx,
 				      (ecc_point *) p);
 	if (ret != 0)
 		return -1;