diff --git a/lib/VMCore/Dominators.cpp b/lib/VMCore/Dominators.cpp
index 5e0ab84cf97..e6e1ffab778 100644
--- a/lib/VMCore/Dominators.cpp
+++ b/lib/VMCore/Dominators.cpp
@@ -403,8 +403,7 @@ BasicBlock *DominatorTreeBase::findNearestCommonDominator(BasicBlock *A,
     return A;
 
   // Collect NodeA dominators set.
-  // SmallPtrSet<DomTreeNode*, 16> NodeADoms;
-  std::set<DomTreeNode*> NodeADoms;
+  SmallPtrSet<DomTreeNode*, 16> NodeADoms;
   NodeADoms.insert(NodeA);
   DomTreeNode *IDomA = NodeA->getIDom();
   while(IDomA) {