diff --git a/include/haproxy/task.h b/include/haproxy/task.h
index 926dfe9ed..02d98156b 100644
--- a/include/haproxy/task.h
+++ b/include/haproxy/task.h
@@ -713,17 +713,21 @@ static inline void _task_schedule(struct task *task, int when, const struct ha_c
 
 #ifdef USE_THREAD
 	if (task->tid < 0) {
-		int was_running;
 		/*
-		 * Make sure the task is not already running before changing
-		 * its expire, otherwise it could overwrite our modification
+		 * If the task is already running, then just wake it up, just
+		 * in case it did not notice it should reschedule itself.
+		 * There is nothing else we can do, if it runs it may
+		 * overwrite the expire field, so we can't just set it, and
+		 * we can afford to wait until it is no longer running, just
+		 * in case we are currently holding a lock, and the running
+		 * task tries to acquire that lock.
+		 * Tasks are supposed to take care of their own scheduling if
+		 * needed anyway, we already do nothing if the task is in the
+		 * runqueue, so it should be okay.
 		 */
-		if (task == th_ctx->current)
-			was_running = 1;
-		else {
-			was_running = 0;
-			while (HA_ATOMIC_FETCH_OR(&task->state, TASK_RUNNING) & TASK_RUNNING)
-				__ha_cpu_relax();
+		if (HA_ATOMIC_FETCH_OR(&task->state, TASK_RUNNING) & TASK_RUNNING) {
+			task_wakeup(task, TASK_WOKEN_OTHER);
+			return;
 		}
 
 		/* FIXME: is it really needed to lock the WQ during the check ? */
@@ -732,8 +736,7 @@ static inline void _task_schedule(struct task *task, int when, const struct ha_c
 			when = tick_first(when, task->expire);
 
 		task->expire = when;
-		if (!was_running)
-			task_drop_running(task, 0);
+		task_drop_running(task, 0);
 		if (!task_in_wq(task) || tick_is_lt(task->expire, task->wq.key)) {
 			if (likely(caller)) {
 				caller = HA_ATOMIC_XCHG(&task->caller, caller);