diff --git a/include/kernaux/multiboot2.h b/include/kernaux/multiboot2.h
index c4466ac..18402c6 100644
--- a/include/kernaux/multiboot2.h
+++ b/include/kernaux/multiboot2.h
@@ -10,6 +10,13 @@ extern "C" {
 
 #define KERNAUX_MULTIBOOT2_MAGIC 0x36d76289
 
+#define KERNAUX_MULTIBOOT2_CHECKSUM(arch, total_size) \
+    ((uint32_t)(-(                                    \
+        ((uint32_t)KERNAUX_MULTIBOOT2_MAGIC) +        \
+        ((uint32_t)(arch)) +                          \
+        ((uint32_t)(total_size))                      \
+    )))
+
 #define KERNAUX_MULTIBOOT2_DATA(ptr) (((uint8_t*)(ptr)) + sizeof(*(ptr)))
 
 #define KERNAUX_MULTIBOOT2_HTAG_NEXT(tag_base) \