diff --git a/drivers/timer/esp32c3_sys_timer.c b/drivers/timer/esp32c3_sys_timer.c
index 367470cadc7..f239de5faad 100644
--- a/drivers/timer/esp32c3_sys_timer.c
+++ b/drivers/timer/esp32c3_sys_timer.c
@@ -65,9 +65,9 @@ static void sys_timer_isr(const void *arg)
 	k_spinlock_key_t key = k_spin_lock(&lock);
 	uint64_t now = get_systimer_alarm();
 
-	uint32_t dticks = (uint32_t)((now - last_count) / CYC_PER_TICK);
+	uint64_t dticks = (uint64_t)((now - last_count) / CYC_PER_TICK);
 
-	last_count = now;
+	last_count += dticks * CYC_PER_TICK;
 
 	if (!TICKLESS) {
 		uint64_t next = last_count + CYC_PER_TICK;
@@ -79,7 +79,7 @@ static void sys_timer_isr(const void *arg)
 	}
 
 	k_spin_unlock(&lock, key);
-	sys_clock_announce(IS_ENABLED(CONFIG_TICKLESS_KERNEL) ? dticks : 1);
+	sys_clock_announce(dticks);
 }
 
 void sys_clock_set_timeout(int32_t ticks, bool idle)