diff --git a/src/xtimer.rs b/src/xtimer.rs
index 8cf2467..b2c5aec 100644
--- a/src/xtimer.rs
+++ b/src/xtimer.rs
@@ -104,10 +104,22 @@ impl XTimer {
         self.get_tick_count = Some(get_tick_count);
         self.cache_timer_num = cache_timer_num;
         self.free_timer_num = 0;
-        self.mut_traverse_timer_list(
-            &mut |timer_list: &mut TimerListListHeadRp| {
-                *timer_list = crate::ListHead::<TimerList>::new_head();
-            });
+        self.work_list = crate::ListHead::<TimerList>::new_head();
+        for i in 0..TVR_SIZE-1 {
+            self.tv1.push(crate::ListHead::<TimerList>::new_head());
+        }
+        for i in 0..TVN_SIZE-1 {
+            self.tv2.push(crate::ListHead::<TimerList>::new_head());
+        }
+        for i in 0..TVN_SIZE-1 {
+            self.tv3.push(crate::ListHead::<TimerList>::new_head());
+        }
+        for i in 0..TVN_SIZE-1 {
+            self.tv4.push(crate::ListHead::<TimerList>::new_head());
+        }
+        for i in 0..TVN_SIZE-1 {
+            self.tv5.push(crate::ListHead::<TimerList>::new_head());
+        }
         match &self.get_tick_count {
             Some(v) => {
                 self.timer_tick = (*v)();
@@ -140,20 +152,6 @@ impl XTimer {
         for_each_cb(&self.tv5);
     }
 
-    fn mut_traverse_timer_list(&mut self, cb: &mut dyn FnMut (&mut TimerListListHeadRp)) {
-        (*cb)(&mut self.work_list);
-        let mut for_each_cb = |tv: &mut [TimerListListHeadRp]| {
-            for i in 0..tv.len() {
-                (*cb)(&mut tv[i]);
-            }
-        };
-        for_each_cb(&mut self.tv1);
-        for_each_cb(&mut self.tv2);
-        for_each_cb(&mut self.tv3);
-        for_each_cb(&mut self.tv4);
-        for_each_cb(&mut self.tv5);
-    }
-
     pub fn uninit(&mut self) {
         self.clear();
     }