diff --git a/client/cmdhfmfhard.c b/client/cmdhfmfhard.c
index cdbd092d8..672064987 100644
--- a/client/cmdhfmfhard.c
+++ b/client/cmdhfmfhard.c
@@ -1385,15 +1385,16 @@ static int acquire_nonces(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_
         flags |= field_off ? 0x0004 : 0;
 
         clearCommandBuffer();
-        SendCommandOLD(CMD_MIFARE_ACQUIRE_ENCRYPTED_NONCES, blockNo + keyType * 0x100, trgBlockNo + trgKeyType * 0x100, flags, key, 6);
+        SendCommandMIX(CMD_MIFARE_ACQUIRE_ENCRYPTED_NONCES, blockNo + keyType * 0x100, trgBlockNo + trgKeyType * 0x100, flags, key, 6);
 
         if (field_off) break;
 
         if (initialize) {
             if (!WaitForResponseTimeout(CMD_ACK, &resp, 3000)) {
+                uint8_t nullkey[6] = {0};
                 //strange second call (iceman)
                 clearCommandBuffer();
-                SendCommandMIX(CMD_MIFARE_ACQUIRE_ENCRYPTED_NONCES, blockNo + keyType * 0x100, trgBlockNo + trgKeyType * 0x100, 4, NULL, 0);
+                SendCommandMIX(CMD_MIFARE_ACQUIRE_ENCRYPTED_NONCES, blockNo + keyType * 0x100, trgBlockNo + trgKeyType * 0x100, 4, nullkey, sizeof(nullkey));
                 return 1;
             }
             if (resp.oldarg[0]) return resp.oldarg[0];  // error during nested_hard