diff --git a/client/src/cmdhfmfdes.c b/client/src/cmdhfmfdes.c
index f63025fa7..a1e1cdd47 100644
--- a/client/src/cmdhfmfdes.c
+++ b/client/src/cmdhfmfdes.c
@@ -5067,7 +5067,7 @@ static int CmdHF14ADesWriteData(const char *Cmd) {
             if (trkeylen > 0) {
                 uint8_t prevReaderID[CRYPTO_AES_BLOCK_SIZE] = {0};
                 DesfireDecodePrevReaderID(&dctx, trkey, transactionCounter, resp, prevReaderID);
-                PrintAndLogEx(INFO, "Prev reader id: %s", resplen, sprint_hex(prevReaderID, CRYPTO_AES_BLOCK_SIZE));
+                PrintAndLogEx(INFO, "Prev reader id: %s", sprint_hex(prevReaderID, CRYPTO_AES_BLOCK_SIZE));
             }
 
             readeridpushed = true;
diff --git a/client/src/mifare/desfirecrypto.c b/client/src/mifare/desfirecrypto.c
index 4342e8ee1..f3c332213 100644
--- a/client/src/mifare/desfirecrypto.c
+++ b/client/src/mifare/desfirecrypto.c
@@ -689,7 +689,7 @@ void DesfireGenTransSessionKeyLRP(uint8_t *key, uint32_t trCntr, uint8_t *uid, b
 
 void DesfireDecodePrevReaderID(DesfireContext *ctx, uint8_t *key, uint32_t trCntr, uint8_t *encPrevReaderID, uint8_t *prevReaderID) {
     uint8_t sessionkey[16] = {0};
-    uint8_t uid[7] = {0};
+    uint8_t uid[12] = {0};
     memcpy(uid, ctx->uid, MAX(ctx->uidlen, 7));
 
     if (ctx->secureChannel == DACEV2) {