diff --git a/client/cmdhfmf.c b/client/cmdhfmf.c
index 4cb9577b..d909cd8c 100644
--- a/client/cmdhfmf.c
+++ b/client/cmdhfmf.c
@@ -906,7 +906,7 @@ int CmdHF14AMfChk(const char *Cmd)
 	char filename[FILE_PATH_SIZE]={0};
 	char buf[13];
 	uint8_t *keyBlock = NULL, *p;
-	uint8_t stKeyBlock = 20;
+	uint16_t stKeyBlock = 20;
 	
 	int i, res;
 	int	keycnt = 0;