diff --git a/armsrc/iclass.c b/armsrc/iclass.c
index c60315620..8019479e5 100644
--- a/armsrc/iclass.c
+++ b/armsrc/iclass.c
@@ -1986,7 +1986,7 @@ void iClass_Dump(uint8_t blockno, uint8_t numblks) {
 }
 
 bool iClass_WriteBlock_ext(uint8_t blockNo, uint8_t *data) {
-	uint8_t write[] = { ICLASS_CMD_UPDATE, blockNo, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
+	uint8_t write[] = { ICLASS_CMD_UPDATE, blockNo, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
 	//uint8_t readblockdata[10];
 	//write[1] = blockNo;
 	memcpy(write+2, data, 12); // data + mac