diff --git a/client/src/cmdhf15.c b/client/src/cmdhf15.c
index 67e47c0d4..9c6c343aa 100644
--- a/client/src/cmdhf15.c
+++ b/client/src/cmdhf15.c
@@ -263,7 +263,6 @@ static int nxp_15693_print_signature(uint8_t *uid, uint8_t *signature) {
     */
 
     uint8_t i;
-    int res;
     bool is_valid = false;
     for (i = 0; i < ARRAYLEN(nxp_15693_public_keys); i++) {
 
@@ -271,14 +270,14 @@ static int nxp_15693_print_signature(uint8_t *uid, uint8_t *signature) {
         uint8_t key[PUBLIC_ECDA_KEYLEN];
         param_gethex_to_eol(nxp_15693_public_keys[i].value, 0, key, PUBLIC_ECDA_KEYLEN, &dl);
 
-        res = ecdsa_signature_r_s_verify(MBEDTLS_ECP_DP_SECP128R1, key, uid, 8, signature, 32, false);
+        int res = ecdsa_signature_r_s_verify(MBEDTLS_ECP_DP_SECP128R1, key, uid, 8, signature, 32, false);
         is_valid = (res == 0);
         if (is_valid)
             break;
     }
 
     PrintAndLogEx(NORMAL, "");
-    if (is_valid == false) {
+    if (is_valid == false || i == ARRAYLEN(nxp_15693_public_keys)) {
         PrintAndLogEx(SUCCESS, "Signature verification " _RED_("failed"));
         return PM3_ESOFT;
     }