diff --git a/client/src/cmdhfmfdes.c b/client/src/cmdhfmfdes.c
index a5bab46dd..3504c85f2 100644
--- a/client/src/cmdhfmfdes.c
+++ b/client/src/cmdhfmfdes.c
@@ -46,12 +46,12 @@ typedef struct {
     uint8_t keyno;
     uint8_t keylen;
     uint8_t key[24];
-} mfdes_authinput_t;
+} PACKED mfdes_authinput_t;
 
 typedef struct mfdes_auth_res {
     uint8_t sessionkeylen;
     uint8_t sessionkey[24];
-} mfdes_auth_res_t;
+} PACKED mfdes_auth_res_t;
 
 typedef struct mfdes_data {
     uint8_t fileno;  //01