diff --git a/Libraries/LibGC/Heap.cpp b/Libraries/LibGC/Heap.cpp
index f6be03c1bd3..2617b04c77f 100644
--- a/Libraries/LibGC/Heap.cpp
+++ b/Libraries/LibGC/Heap.cpp
@@ -119,6 +119,7 @@ public:
             m_all_live_heap_blocks.set(&block);
             return IterationDecision::Continue;
         });
+        m_work_queue.ensure_capacity(roots.size());
 
         for (auto& [root, root_origin] : roots) {
             auto& graph_node = m_graph.ensure(bit_cast<FlatPtr>(root));