trivial: guard with pragma once
diff --git a/libsel4utils/arch_include/riscv/sel4utils/arch/util.h b/libsel4utils/arch_include/riscv/sel4utils/arch/util.h
index c22c109..bdb03c3 100644
--- a/libsel4utils/arch_include/riscv/sel4utils/arch/util.h
+++ b/libsel4utils/arch_include/riscv/sel4utils/arch/util.h
@@ -9,8 +9,7 @@
  *
  * @TAG(DATA61_BSD)
  */
-#ifndef _SEL4UTILS_ARCH_UTIL_H
-#define _SEL4UTILS_ARCH_UTIL_H
+#pragma once
 
 #include <stdint.h>
 #include <sel4/sel4.h>
@@ -51,4 +50,3 @@
     regs->sp = value;
 }
 
-#endif /* _SEL4UTILS_ARCH_UTIL_H */