diff --git a/llvm/lib/CodeGen/MachineCSE.cpp b/llvm/lib/CodeGen/MachineCSE.cpp
index 0715f28c..9d46aaa 100644
--- a/llvm/lib/CodeGen/MachineCSE.cpp
+++ b/llvm/lib/CodeGen/MachineCSE.cpp
@@ -255,6 +255,7 @@
 
     if (I == EE) {
       assert(CrossMBB && "Reaching end-of-MBB without finding MI?");
+      (void)CrossMBB;
       CrossMBB = false;
       NonLocal = true;
       I = MBB->begin();