diff --git a/client/mifare/mifarehost.c b/client/mifare/mifarehost.c
index a9fbaac77..2f49b578e 100644
--- a/client/mifare/mifarehost.c
+++ b/client/mifare/mifarehost.c
@@ -407,9 +407,9 @@ static int nested_fixed_nonce(StateList_t statelist, uint32_t fixed_nt, uint32_t
 	}
 
 	// test each {ar} response
-	uint32_t key_index;
+	size_t key_index;
 
-	int isOK = mfCheckKeysFixedNonce(statelist.blockNo, statelist.keyType, authentication_timeout, true, num_ar_par, ar_par, &key_index);
+	int isOK = mfCheckKeysFixedNonce(statelist.blockNo, statelist.keyType, authentication_timeout, true, num_ar_par, ar_par, (uint32_t*)&key_index);
 
 	if (isOK == 0) {     // success, key found
 		// key_index contains the index into the cypher state list
diff --git a/common/mbedtls/cmac.c b/common/mbedtls/cmac.c
index db4a71d72..d8738c508 100644
--- a/common/mbedtls/cmac.c
+++ b/common/mbedtls/cmac.c
@@ -427,7 +427,7 @@ int mbedtls_cipher_cmac( const mbedtls_cipher_info_t *cipher_info,
  */
 int mbedtls_aes_cmac_prf_128( const unsigned char *key, size_t key_length,
                               const unsigned char *input, size_t in_len,
-                              unsigned char *output )
+                              unsigned char output[16] )
 {
     int ret;
     const mbedtls_cipher_info_t *cipher_info;