diff --git a/lib_fiber/c/src/fiber_io.c b/lib_fiber/c/src/fiber_io.c
index 5fa43272a..7a961b9ae 100644
--- a/lib_fiber/c/src/fiber_io.c
+++ b/lib_fiber/c/src/fiber_io.c
@@ -532,7 +532,8 @@ void fiber_file_set(FILE_EVENT *fe)
 	}
 
 	if (__thread_fiber->events[fe->fd] != NULL) {
-		printf("%s(%d): exist fd=%d\r\n", __FUNCTION__, __LINE__, fe->fd);
+		printf("%s(%d): exist fd=%d, old=%p new=%p\r\n", __FUNCTION__,
+			__LINE__, fe->fd, __thread_fiber->events[fe->fd], fe);
 		abort();
 	}
 
@@ -692,9 +693,16 @@ void fiber_file_close(FILE_EVENT *fe)
 FILE_EVENT *fiber_file_cache_get(socket_t fd)
 {
 	FILE_EVENT *fe;
+	int exist = 0;
 
 	fiber_io_check();
-	fe = (FILE_EVENT*) array_pop_back(__thread_fiber->cache);
+
+	fe = fiber_file_get(fd);
+	if (fe == NULL) {
+		fe = (FILE_EVENT*) array_pop_back(__thread_fiber->cache);
+	} else { // Why? the fe wasn't removed by fiber_file_cache_put ?
+		exist = 1;
+	}
 	if (fe == NULL) {
 		fe = file_event_alloc(fd);
 	} else {
@@ -706,7 +714,9 @@ FILE_EVENT *fiber_file_cache_get(socket_t fd)
 		fe->mask |= EVENT_DIRECT;
 	}
 #endif
-	fiber_file_set(fe);
+	if (!exist) {
+		fiber_file_set(fe);
+	}
 	return fe;
 }
 
diff --git a/lib_fiber/c/src/sync/sync_timer.c b/lib_fiber/c/src/sync/sync_timer.c
index b5ad2aac2..9b1f36274 100644
--- a/lib_fiber/c/src/sync/sync_timer.c
+++ b/lib_fiber/c/src/sync/sync_timer.c
@@ -12,6 +12,7 @@ struct SYNC_TIMER {
 	MBOX *box;
 	int stop;
 	TIMER_CACHE *waiters;
+	unsigned long tid;
 };
 
 static SYNC_TIMER *sync_timer_new(void)
@@ -23,6 +24,7 @@ static SYNC_TIMER *sync_timer_new(void)
 	pthread_mutex_init(&timer->lock, NULL);
 	timer->box = mbox_create(MBOX_T_MPSC);
 	timer->waiters = timer_cache_create();
+	timer->tid = __pthread_self();
 
 	out = mbox_out(timer->box);
 	assert(out != INVALID_SOCKET);
@@ -204,12 +206,24 @@ void sync_timer_wakeup(SYNC_TIMER *timer, SYNC_OBJ *obj)
 
 	if (var_hook_sys_api) {
 		socket_t out = mbox_out(timer->box);
-		FILE_EVENT *fe = fiber_file_cache_get(out);
+		FILE_EVENT *fe;
+		int same_thread;
+
+		if (__pthread_self() == timer->tid) {
+			fe = fiber_file_open_write(out);
+			same_thread = 1;
+		} else {
+			fe = fiber_file_cache_get(out);
+			same_thread = 0;
+		}
 
 		fe->mask |= EVENT_SYSIO;
 
 		mbox_send(timer->box, msg);
-		fiber_file_cache_put(fe);
+
+		if (!same_thread) {
+			fiber_file_cache_put(fe);
+		}
 	} else {
 		mbox_send(timer->box, msg);
 	}