diff --git a/lib/CodeGen/VirtRegRewriter.cpp b/lib/CodeGen/VirtRegRewriter.cpp
index a859d80..61ea80b 100644
--- a/lib/CodeGen/VirtRegRewriter.cpp
+++ b/lib/CodeGen/VirtRegRewriter.cpp
@@ -491,7 +491,7 @@
                           const TargetRegisterInfo *TRI,
                           VirtRegMap &VRM) {
   MachineInstr *ReMatDefMI = VRM.getReMaterializedMI(Reg);
-#ifdef NDEBUG
+#ifndef NDEBUG
   const TargetInstrDesc &TID = ReMatDefMI->getDesc();
   assert(TID.getNumDefs() != 1 &&
          "Don't know how to remat instructions that define > 1 values!");