diff --git a/tools/eficapsule.h b/tools/eficapsule.h
index 072a4b5598b5cf93432d9dde51a8e905c3741c8d..6ffed6cc59cbae920115c029ecc5dad5b58c3e58 100644
--- a/tools/eficapsule.h
+++ b/tools/eficapsule.h
@@ -63,7 +63,7 @@ struct efi_firmware_management_capsule_header {
 	uint32_t version;
 	uint16_t embedded_driver_count;
 	uint16_t payload_item_count;
-	uint32_t item_offset_list[];
+	uint64_t item_offset_list[];
 } __packed;
 
 /* image_capsule_support */