diff --git a/mirai-core/src/commonTest/kotlin/network/framework/components/EventDispatcherImpl.kt b/mirai-core/src/commonTest/kotlin/network/framework/components/EventDispatcherImpl.kt
index d38f171db..fb6b6a99d 100644
--- a/mirai-core/src/commonTest/kotlin/network/framework/components/EventDispatcherImpl.kt
+++ b/mirai-core/src/commonTest/kotlin/network/framework/components/EventDispatcherImpl.kt
@@ -1,15 +1,16 @@
 /*
- * Copyright 2019-2021 Mamoe Technologies and contributors.
+ * Copyright 2019-2022 Mamoe Technologies and contributors.
  *
- *  此源代码的使用受 GNU AFFERO GENERAL PUBLIC LICENSE version 3 许可证的约束, 可以在以下链接找到该许可证.
- *  Use of this source code is governed by the GNU AGPLv3 license that can be found through the following link.
+ * 此源代码的使用受 GNU AFFERO GENERAL PUBLIC LICENSE version 3 许可证的约束, 可以在以下链接找到该许可证.
+ * Use of this source code is governed by the GNU AGPLv3 license that can be found through the following link.
  *
- *  https://github.com/mamoe/mirai/blob/master/LICENSE
+ * https://github.com/mamoe/mirai/blob/dev/LICENSE
  */
 
 package network.framework.components
 
 import kotlinx.coroutines.CoroutineStart
+import kotlinx.coroutines.isActive
 import kotlinx.coroutines.job
 import kotlinx.coroutines.launch
 import net.mamoe.mirai.event.Event
@@ -26,13 +27,21 @@ internal open class TestEventDispatcherImpl(
 ) : EventDispatcherImpl(lifecycleContext, logger) {
     override suspend fun broadcast(event: Event) {
         runUnwrapCancellationException {
-            launch(
-                EventDispatcherScopeFlag,
-                start = CoroutineStart.UNDISPATCHED
-            ) {
+            if (isActive) {
+                // This requires the scope to be active, while the original one doesn't.
+
+                // so that [joinBroadcast] works.
+                launch(
+                    EventDispatcherScopeFlag,
+                    start = CoroutineStart.UNDISPATCHED
+                ) {
+                    super.broadcast(event)
+                }.join()
+            } else {
+                // Scoped closed, typically when broadcasting `BotOfflineEvent` by StateObserver from `bot.close`
                 super.broadcast(event)
-            }.join()
-        } // so that [joinBroadcast] works.
+            }
+        }
     }
 
     @OptIn(TestOnly::class)