diff --git a/client/src/mifare/desfirecore.c b/client/src/mifare/desfirecore.c
index d06691744..c348fd3a9 100644
--- a/client/src/mifare/desfirecore.c
+++ b/client/src/mifare/desfirecore.c
@@ -1404,8 +1404,8 @@ static int DesfireAuthenticateEV1(DesfireContext_t *dctx, DesfireSecureChannel s
     DesfireCryptoEncDecEx(dctx, DCOMainKey, encRndB, rndlen, RndB, false, false, IV);
 
     if (g_debugMode > 1) {
-        PrintAndLogEx(DEBUG, "encRndB: %s", sprint_hex(encRndB, 8));
-        PrintAndLogEx(DEBUG, "RndB: %s", sprint_hex(RndB, 8));
+        PrintAndLogEx(DEBUG, "encRndB: %s", sprint_hex(encRndB, rndlen));
+        PrintAndLogEx(DEBUG, "RndB: %s", sprint_hex(RndB, rndlen));
     }
 
     // - Rotate RndB by 8 bits
@@ -1435,7 +1435,7 @@ static int DesfireAuthenticateEV1(DesfireContext_t *dctx, DesfireSecureChannel s
         memcpy(tmp + rndlen, rotRndB, rndlen);
         if (g_debugMode > 1) {
             PrintAndLogEx(DEBUG, "rotRndB: %s", sprint_hex(rotRndB, rndlen));
-            PrintAndLogEx(DEBUG, "Both   : %s", sprint_hex(tmp, 32));
+            PrintAndLogEx(DEBUG, "Both   : %s", sprint_hex(tmp, rndlen * 2));
         }
         DesfireCryptoEncDecEx(dctx, DCOMainKey, tmp, rndlen * 2, both, true, true, IV);
     }