diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index 1f670028bf19..a018034dd81c 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -5923,6 +5923,20 @@ static void scx_disable(struct scx_sched *sch, enum scx_exit_kind kind)
 		irq_work_queue(&sch->disable_irq_work);
 }
 
+/**
+ * scx_flush_disable_work - flush the disable work and wait for it to finish
+ * @sch: the scheduler
+ *
+ * sch->disable_work might still not queued, causing kthread_flush_work()
+ * as a noop. Syncing the irq_work first is required to guarantee the
+ * kthread work has been queued before waiting for it.
+ */
+static void scx_flush_disable_work(struct scx_sched *sch)
+{
+	irq_work_sync(&sch->disable_irq_work);
+	kthread_flush_work(&sch->disable_work);
+}
+
 static void dump_newline(struct seq_buf *s)
 {
 	trace_sched_ext_dump("");
@@ -6823,7 +6837,7 @@ static void scx_root_enable_workfn(struct kthread_work *work)
 	 * completion. sch's base reference will be put by bpf_scx_unreg().
 	 */
 	scx_error(sch, "scx_root_enable() failed (%d)", ret);
-	kthread_flush_work(&sch->disable_work);
+	scx_flush_disable_work(sch);
 	cmd->ret = 0;
 }
 
@@ -7090,7 +7104,7 @@ static void scx_sub_enable_workfn(struct kthread_work *work)
 	percpu_up_write(&scx_fork_rwsem);
 err_disable:
 	mutex_unlock(&scx_enable_mutex);
-	kthread_flush_work(&sch->disable_work);
+	scx_flush_disable_work(sch);
 	cmd->ret = 0;
 }
 
@@ -7351,7 +7365,7 @@ static void bpf_scx_unreg(void *kdata, struct bpf_link *link)
 	struct scx_sched *sch = rcu_dereference_protected(ops->priv, true);
 
 	scx_disable(sch, SCX_EXIT_UNREG);
-	kthread_flush_work(&sch->disable_work);
+	scx_flush_disable_work(sch);
 	RCU_INIT_POINTER(ops->priv, NULL);
 	kobject_put(&sch->kobj);
 }