diff --git a/boot/bootutil/include/bootutil/crypto/ecdsa_p256.h b/boot/bootutil/include/bootutil/crypto/ecdsa_p256.h
index faa8ea3..b77cd34 100644
--- a/boot/bootutil/include/bootutil/crypto/ecdsa_p256.h
+++ b/boot/bootutil/include/bootutil/crypto/ecdsa_p256.h
@@ -69,7 +69,7 @@
     (void)ctx;
 }
 
-static inline int bootutil_ecdsa_p256_verify(bootutil_ecdsa_p256_context *ctx, const uint8_t *pk, const uint8_t *hash, const uint8_t *sig)
+static inline int bootutil_ecdsa_p256_verify(bootutil_ecdsa_p256_context *ctx, uint8_t *pk, uint8_t *hash, uint8_t *sig)
 {
     (void)ctx;
     return cc310_ecdsa_verify_secp256r1(hash, pk, sig, BOOTUTIL_CRYPTO_ECDSA_P256_HASH_SIZE);
diff --git a/boot/bootutil/src/image_ec256.c b/boot/bootutil/src/image_ec256.c
index 185624c..f5b8135 100644
--- a/boot/bootutil/src/image_ec256.c
+++ b/boot/bootutil/src/image_ec256.c
@@ -30,6 +30,9 @@
 
 #ifdef MCUBOOT_SIGN_EC256
 /*TODO: remove this after cypress port mbedtls to abstract crypto api */
+#ifdef MCUBOOT_USE_CC310
+#define NUM_ECC_BYTES (256 / 8)
+#endif
 #if defined (MCUBOOT_USE_TINYCRYPT) || defined (MCUBOOT_USE_CC310)
 #include "bootutil/sign_key.h"
 
diff --git a/boot/zephyr/nrf52840dk_nrf52840_cc310_ecdsa.conf b/boot/zephyr/nrf52840dk_nrf52840_cc310_ecdsa.conf
new file mode 100644
index 0000000..d195965
--- /dev/null
+++ b/boot/zephyr/nrf52840dk_nrf52840_cc310_ecdsa.conf
@@ -0,0 +1,2 @@
+CONFIG_BOOT_SIGNATURE_TYPE_ECDSA_P256=y
+CONFIG_BOOT_ECDSA_CC310=y