Index: kernel/arch/amd64/src/boot/memmap.c
===================================================================
--- kernel/arch/amd64/src/boot/memmap.c	(revision e80329d664f5d49f31f3da70a215121f490db79d)
+++ kernel/arch/amd64/src/boot/memmap.c	(revision 7e752b2a0d66c871748e5fa9e8bbe3a27c70a202)
@@ -35,5 +35,5 @@
 #include <arch/boot/memmap.h>
 
-uint8_t e820counter = 0xff;
+uint8_t e820counter = 0xffU;
 e820memmap_t e820table[MEMMAP_E820_MAX_RECORDS];