diff --git a/lib/CodeGen/StrongPHIElimination.cpp b/lib/CodeGen/StrongPHIElimination.cpp
index 9a8e74599c6..5b061950464 100644
--- a/lib/CodeGen/StrongPHIElimination.cpp
+++ b/lib/CodeGen/StrongPHIElimination.cpp
@@ -672,6 +672,7 @@ void StrongPHIElimination::InsertCopiesForPHI(MachineInstr *PHI,
       LiveInterval &SrcInterval = LI->getInterval(SrcReg);
       SlotIndex PredIndex = LI->getMBBEndIdx(PredBB);
       VNInfo *SrcVNI = SrcInterval.getVNInfoBefore(PredIndex);
+      (void)SrcVNI;
       assert(SrcVNI);
       continue;
     }