diff --git a/litex/soc/software/bios/boot.c b/litex/soc/software/bios/boot.c
index 8560c0fe8..7a7b3b76f 100644
--- a/litex/soc/software/bios/boot.c
+++ b/litex/soc/software/bios/boot.c
@@ -260,7 +260,7 @@ int serialboot(void)
 
 				/* Copy payload */
 				load_addr = (char *)(uintptr_t) get_uint32(&frame.payload[0]);
-				memcpy(load_addr, &frame.payload[4], frame.payload_length);
+				memcpy(load_addr, &frame.payload[4], frame.payload_length - 4);
 
 				/* Acknowledge and continue */
 				uart_write(SFL_ACK_SUCCESS);