diff --git a/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp b/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp
index c583eea14d62..ab736c1de877 100644
--- a/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp
@@ -73,6 +73,8 @@ namespace {
       AU.addPreservedID(LoopSimplifyID);
       AU.addRequired<LoopInfo>();
       AU.addPreserved<LoopInfo>();
+      AU.addRequiredID(LCSSAID);
+      AU.addPreservedID(LCSSAID);
     }
 
   private:
@@ -199,6 +201,8 @@ bool LoopUnswitch::visitLoop(Loop *L) {
       }
   }
     
+  assert(L->isLCSSAForm());
+  
   return Changed;
 }