diff --git a/arch/arm64/src/common/arm64_arch_timer.c b/arch/arm64/src/common/arm64_arch_timer.c
index 72173b1979..4500a1fad5 100644
--- a/arch/arm64/src/common/arm64_arch_timer.c
+++ b/arch/arm64/src/common/arm64_arch_timer.c
@@ -58,7 +58,7 @@ static inline void arm64_arch_timer_set_compare(uint64_t value)
   write_sysreg(value, cntv_cval_el0);
 }
 
-static inline void arm64_arch_timer_enable(unsigned char enable)
+static inline void arm64_arch_timer_enable(bool enable)
 {
   uint64_t value;