diff --git a/armsrc/mifarecmd.c b/armsrc/mifarecmd.c
index 2eed2ca5c6..9820d19a2f 100644
--- a/armsrc/mifarecmd.c
+++ b/armsrc/mifarecmd.c
@@ -3482,7 +3482,7 @@ void MifareGen3Blk(uint8_t block_len, uint8_t *block) {
             retval = PM3_ESOFT;
             goto OUT;
         }
-        cmd[ofs] = block_len < card_info->uidlen ? card_info->sak : cmd[ofs];
+        cmd[ofs] = block_len <= card_info->uidlen ? card_info->sak : cmd[ofs];
         ofs++;
         cmd[ofs++] = card_info->atqa[0];
         cmd[ofs++] = card_info->atqa[1];
diff --git a/client/src/cmdhfmf.c b/client/src/cmdhfmf.c
index 2bfd6a020a..e61a6a7e9c 100644
--- a/client/src/cmdhfmf.c
+++ b/client/src/cmdhfmf.c
@@ -7202,7 +7202,8 @@ static int CmdHf14AGen3Block(const char *Cmd) {
                   " - You can specify part of manufacturer block as\n"
                   "   4/7-bytes for UID change only\n"
                   "\n"
-                  "NOTE: BCC, SAK, ATQA will be calculated automatically"
+                  "NOTE: BCC and ATQA will be calculated automatically\n"
+                  "SAK will be automatically set to default values if not specified"
                   ,
                   "hf mf gen3blk                      --> print current data\n"
                   "hf mf gen3blk -d 01020304          --> set 4 byte uid\n"