diff --git a/headers/private/kernel/arch/x86/arch_kernel.h b/headers/private/kernel/arch/x86/arch_kernel.h
index 418d707c47..00e2ea868d 100644
--- a/headers/private/kernel/arch/x86/arch_kernel.h
+++ b/headers/private/kernel/arch/x86/arch_kernel.h
@@ -18,7 +18,7 @@
 #define KERNEL_TOP  (KERNEL_BASE + (KERNEL_SIZE - 1))
 
 #ifdef _BOOT_MODE
-# define KERNEL_BASE_64BIT 0xffffffff80000000
+# define KERNEL_BASE_64BIT 0xffffffff80000000ll
 #endif
 
 /* User space layout is a little special:
diff --git a/headers/private/kernel/arch/x86_64/arch_kernel.h b/headers/private/kernel/arch/x86_64/arch_kernel.h
index 612f0adff8..e19b5c25b8 100644
--- a/headers/private/kernel/arch/x86_64/arch_kernel.h
+++ b/headers/private/kernel/arch/x86_64/arch_kernel.h
@@ -20,7 +20,7 @@
 // The whole kernel address space is the top 512GB of the address space.
 #ifdef _BOOT_MODE
 # define KERNEL_BASE			0x80000000
-# define KERNEL_BASE_64BIT		0xffffffff80000000
+# define KERNEL_BASE_64BIT		0xffffffff80000000ll
 #else
 # define KERNEL_BASE			0xffffff8000000000
 #endif