diff --git a/src/hsm/hsm2040.h b/src/hsm/hsm2040.h
index b63a70e..72bb9a1 100644
--- a/src/hsm/hsm2040.h
+++ b/src/hsm/hsm2040.h
@@ -57,8 +57,8 @@ struct apdu {
   uint8_t *res_apdu_data;
 };
 
-#define MAX_CMD_APDU_DATA_SIZE (24+4+256+256)
-#define MAX_RES_APDU_DATA_SIZE (5+9+512)
+#define MAX_CMD_APDU_DATA_SIZE (24+4+512*4)
+#define MAX_RES_APDU_DATA_SIZE (5+9+512*4)
 #define CCID_MSG_HEADER_SIZE    10
 #define USB_LL_BUF_SIZE         64