# Pastebin EzE9l2PE
diff --git a/src/system/kernel/scheduler/scheduler_thread.h b/src/system/kernel/scheduler/scheduler_thread.h
index 916f77cb77..c9a21bde60 100644
--- a/src/system/kernel/scheduler/scheduler_thread.h
+++ b/src/system/kernel/scheduler/scheduler_thread.h
@@ -410,6 +410,9 @@ inline void
 ThreadData::Enqueue(bool& wasRunQueueEmpty)
 {
 	SCHEDULER_ENTER_FUNCTION();
+	ASSERT(fThread->state == B_THREAD_READY
+		|| fThread->state == B_THREAD_SUSPENDED
+		|| fThread->state == B_THREAD_WAITING);
 
 	if (!fReady) {
 		if (gTrackCoreLoad) {