diff --git a/client/src/cmdhffido.c b/client/src/cmdhffido.c
index 64ab28687..5af098c6a 100644
--- a/client/src/cmdhffido.c
+++ b/client/src/cmdhffido.c
@@ -343,7 +343,7 @@ static int CmdHFFidoRegister(const char *cmd) {
                          &data[0], 32,            // challenge parameter
                          &buf[67], keyHandleLen,  // keyHandle
                          &buf[1], 65,             // user public key
-                         NULL, 0);
+                         (uint8_t *)NULL, 0);
         (void)res;
         //PrintAndLogEx(INFO, "--xbuf(%d)[%d]: %s", res, xbuflen, sprint_hex(xbuf, xbuflen));
         res = ecdsa_signature_verify(MBEDTLS_ECP_DP_SECP256R1, public_key, xbuf, xbuflen, &buf[hashp], len - hashp, true);
@@ -616,7 +616,7 @@ static int CmdHFFidoAuthenticate(const char *cmd) {
                              &buf[0], 1,    // user presence
                              &buf[1], 4,    // counter
                              data, 32,      // challenge parameter
-                             NULL, 0);
+                             (uint8_t *)NULL, 0);
             (void)res;
             //PrintAndLogEx(INFO, "--xbuf(%d)[%d]: %s", res, xbuflen, sprint_hex(xbuf, xbuflen));
             res = ecdsa_signature_verify(MBEDTLS_ECP_DP_SECP256R1, public_key, xbuf, xbuflen, &buf[5], len - 5, true);
diff --git a/client/src/emv/emv_pki.c b/client/src/emv/emv_pki.c
index 456e2960a..365e2ca63 100644
--- a/client/src/emv/emv_pki.c
+++ b/client/src/emv/emv_pki.c
@@ -191,7 +191,7 @@ static struct emv_pk *emv_pki_decode_key_ex(const struct emv_pk *enc_pk,
                                   exp_tlv,
                                   add_tlv,
                                   sdatl_tlv,
-                                  NULL);
+                                  (uint8_t *)NULL);
     if (!data || data_len < 11 + pan_length) {
         PrintAndLogEx(WARNING, "ERROR: Can't decode message");
         return NULL;
@@ -365,7 +365,7 @@ struct tlvdb *emv_pki_recover_dac_ex(const struct emv_pk *enc_pk, const struct t
                                                  3,
                                                  sda_tlv,
                                                  &sda_tdata,
-                                                 NULL);
+                                                 (uint8_t *)NULL);
 
     free(sdatl); // malloc here: emv_pki_sdatl_fill
 
@@ -396,7 +396,7 @@ struct tlvdb *emv_pki_recover_idn_ex(const struct emv_pk *enc_pk, const struct t
                                                  tlvdb_get(db, 0x9f4b, NULL),
                                                  2,
                                                  dyn_tlv,
-                                                 NULL);
+                                                 (uint8_t *)NULL);
 
     if (!data || data_len < 3)
         return NULL;
@@ -432,7 +432,7 @@ struct tlvdb *emv_pki_recover_atc_ex(const struct emv_pk *enc_pk, const struct t
                                                  tlvdb_get(db, 0x9f02, NULL),
                                                  tlvdb_get(db, 0x5f2a, NULL),
                                                  tlvdb_get(db, 0x9f69, NULL),
-                                                 NULL);
+                                                 (uint8_t *)NULL);
 
     if (!data || data_len < 3)
         return NULL;
@@ -502,7 +502,7 @@ struct tlvdb *emv_pki_perform_cda_ex(const struct emv_pk *enc_pk, const struct t
                                                  tlvdb_get(this_db, 0x9f4b, NULL),
                                                  2,
                                                  un_tlv,
-                                                 NULL);
+                                                 (uint8_t *)NULL);
     if (!data || data_len < 3) {
         PrintAndLogEx(WARNING, "ERROR: can't decode message. [%zu bytes]", data_len);
         return NULL;
diff --git a/client/src/emv/emv_pki_priv.c b/client/src/emv/emv_pki_priv.c
index 383f3d7f5..c288c4342 100644
--- a/client/src/emv/emv_pki_priv.c
+++ b/client/src/emv/emv_pki_priv.c
@@ -204,7 +204,7 @@ static struct tlvdb *emv_pki_sign_key(const struct crypto_pk *cp,
                                             msg, pos,
                                             tlvdb_get(exp_db, exp_tag, NULL),
                                             add_tlv,
-                                            NULL);
+                                            (uint8_t *)NULL);
     free(msg);
     if (!db) {
         free(exp_db);
@@ -244,7 +244,7 @@ struct tlvdb *emv_pki_sign_dac(const struct crypto_pk *cp, const struct tlv *dac
                                             0x93, 0,
                                             msg, pos,
                                             sda_tlv,
-                                            NULL);
+                                            (uint8_t *)NULL);
 
     free(msg);
 
@@ -269,7 +269,7 @@ struct tlvdb *emv_pki_sign_idn(const struct crypto_pk *cp, const struct tlv *idn
                                             0x9f4b, 0,
                                             msg, pos,
                                             dyn_tlv,
-                                            NULL);
+                                            (uint8_t *)NULL);
 
     free(msg);