diff --git a/lib/Passes/PassBuilder.cpp b/lib/Passes/PassBuilder.cpp
index 4845bd2957b..abc53e97aa7 100644
--- a/lib/Passes/PassBuilder.cpp
+++ b/lib/Passes/PassBuilder.cpp
@@ -341,10 +341,7 @@ PassBuilder::buildFunctionSimplificationPipeline(OptimizationLevel Level,
   // Rotate Loop - disable header duplication at -Oz
   LPM1.addPass(LoopRotatePass(Level != Oz));
   LPM1.addPass(LICMPass());
-#if 0
-  // The LoopUnswitch pass isn't yet ported to the new pass manager.
-  LPM1.addPass(LoopUnswitchPass(/* OptimizeForSize */ Level != O3));
-#endif
+  LPM1.addPass(SimpleLoopUnswitchPass());
   LPM2.addPass(IndVarSimplifyPass());
   LPM2.addPass(LoopIdiomRecognizePass());
   LPM2.addPass(LoopDeletionPass());
diff --git a/test/Other/new-pm-defaults.ll b/test/Other/new-pm-defaults.ll
index f712dc7b63c..0ec356392a2 100644
--- a/test/Other/new-pm-defaults.ll
+++ b/test/Other/new-pm-defaults.ll
@@ -95,6 +95,7 @@
 ; CHECK-O-NEXT: Running pass: LoopRotatePass
 ; CHECK-O-NEXT: Running pass: LICM
 ; CHECK-O-NEXT: Running analysis: OuterAnalysisManagerProxy
+; CHECK-O-NEXT: Running pass: SimpleLoopUnswitchPass
 ; CHECK-O-NEXT: Finished Loop pass manager run.
 ; CHECK-O-NEXT: Running pass: SimplifyCFGPass
 ; CHECK-O-NEXT: Running pass: InstCombinePass