diff --git a/kernel/src/arch/x86_64/CPU.h b/kernel/src/arch/x86_64/CPU.h
index 9e81fd41..a06de7b9 100644
--- a/kernel/src/arch/x86_64/CPU.h
+++ b/kernel/src/arch/x86_64/CPU.h
@@ -1,3 +1,4 @@
+#pragma once
 #include <luna/Types.h>
 
 struct Registers // Saved CPU registers for x86-64