diff --git a/src/mark-compact.cc b/src/mark-compact.cc
index 7e7a3439d2..3d1af7cdb4 100644
--- a/src/mark-compact.cc
+++ b/src/mark-compact.cc
@@ -400,7 +400,6 @@ void MarkCompactCollector::CollectGarbage() {
   // Make sure that Prepare() has been called. The individual steps below will
   // update the state as they proceed.
   ASSERT(state_ == PREPARE_GC);
-  ASSERT(encountered_weak_collections_ == Smi::FromInt(0));
 
   MarkLiveObjects();
   ASSERT(heap_->incremental_marking()->IsStopped());