diff --git a/tools/kwbimage.c b/tools/kwbimage.c
index ec52f9ee43b7ce01fd656165e039a08bc5d472a1..c50f2e2b2494d56c5f34e7660b54b0cb9752597d 100644
--- a/tools/kwbimage.c
+++ b/tools/kwbimage.c
@@ -325,7 +325,7 @@ static void *image_create_v0(size_t *imagesz, struct image_tool_params *params,
 	main_hdr = image;
 
 	/* Fill in the main header */
-	main_hdr->blocksize = payloadsz + sizeof(uint32_t);
+	main_hdr->blocksize = payloadsz + sizeof(uint32_t) - headersz;
 	main_hdr->srcaddr   = headersz;
 	main_hdr->ext       = has_ext;
 	main_hdr->destaddr  = params->addr;
@@ -811,8 +811,8 @@ static void kwbimage_print_header(const void *ptr)
 
 	printf("Image Type:   MVEBU Boot from %s Image\n",
 	       image_boot_mode_name(mhdr->blockid));
-	printf("Data Size:    ");
 	printf("Image version:%d\n", image_version((void *)ptr));
+	printf("Data Size:    ");
 	genimg_print_size(mhdr->blocksize - sizeof(uint32_t));
 	printf("Load Address: %08x\n", mhdr->destaddr);
 	printf("Entry Point:  %08x\n", mhdr->execaddr);
@@ -835,7 +835,8 @@ static int kwbimage_verify_header(unsigned char *ptr, int image_size,
 
 	main_hdr = (void *)ptr;
 	checksum = image_checksum8(ptr,
-				   sizeof(struct main_hdr_v0));
+				   sizeof(struct main_hdr_v0)
+				   - sizeof(uint8_t));
 	if (checksum != main_hdr->checksum)
 		return -FDT_ERR_BADSTRUCTURE;
 
@@ -843,7 +844,8 @@ static int kwbimage_verify_header(unsigned char *ptr, int image_size,
 	if (image_version((void *)ptr) == 0) {
 		ext_hdr = (void *)ptr + sizeof(struct main_hdr_v0);
 		checksum = image_checksum8(ext_hdr,
-					   sizeof(struct ext_hdr_v0));
+					   sizeof(struct ext_hdr_v0)
+					   - sizeof(uint8_t));
 		if (checksum != ext_hdr->checksum)
 			return -FDT_ERR_BADSTRUCTURE;
 	}