diff --git a/kern/ispinlock.c b/kern/ispinlock.c
index 4a7b751..01965f8 100644
--- a/kern/ispinlock.c
+++ b/kern/ispinlock.c
@@ -19,7 +19,7 @@ void spin_unlock(spinlock_t *l) {
 
 // Optional: tiny pause/backoff (works even if Zihintpause isn't present).
 // See: https://github.com/riscv/riscv-isa-manual/blob/main/src/zihintpause.adoc
-void cpu_relax(void) {
+static inline void cpu_relax(void) {
 #if defined(__riscv_zihintpause)
     __asm__ volatile("pause");
 #else
diff --git a/kern/ispinlock.h b/kern/ispinlock.h
index e0303d6..d71af17 100644
--- a/kern/ispinlock.h
+++ b/kern/ispinlock.h
@@ -8,5 +8,4 @@ typedef struct {
 void spinlock_init(spinlock_t *l);
 bool spin_trylock(spinlock_t *l);
 void spin_unlock(spinlock_t *l);
-void cpu_relax(void);
 void spin_lock(spinlock_t *l);