diff --git a/headers/private/kernel/vm/VMCache.h b/headers/private/kernel/vm/VMCache.h
index a4994847a8..924d8c9139 100644
--- a/headers/private/kernel/vm/VMCache.h
+++ b/headers/private/kernel/vm/VMCache.h
@@ -297,6 +297,7 @@ VMCache::ReleaseRefAndUnlock(bool consumerLocked)
 void
 VMCache::MarkPageUnbusy(vm_page* page)
 {
+	ASSERT(page->busy);
 	page->busy = false;
 	NotifyPageEvents(page, PAGE_EVENT_NOT_BUSY);
 }