diff --git a/llvm/lib/CodeGen/MachineDominators.cpp b/llvm/lib/CodeGen/MachineDominators.cpp
index 04c8ecb..df60cf3 100644
--- a/llvm/lib/CodeGen/MachineDominators.cpp
+++ b/llvm/lib/CodeGen/MachineDominators.cpp
@@ -35,6 +35,8 @@
 }
 
 bool MachineDominatorTree::runOnMachineFunction(MachineFunction &F) {
+  CriticalEdgesToSplit.clear();
+  NewBBs.clear();
   DT->recalculate(F);
 
   return false;