diff --git a/llvm/lib/Transforms/Utils/LowerSwitch.cpp b/llvm/lib/Transforms/Utils/LowerSwitch.cpp
@@ -148,13 +148,6 @@ bool LowerSwitch::runOnFunction(Function &F) {
   LazyValueInfo *LVI = &getAnalysis<LazyValueInfoWrapperPass>().getLVI();
   auto *ACT = getAnalysisIfAvailable<AssumptionCacheTracker>();
   AssumptionCache *AC = ACT ? &ACT->getAssumptionCache(F) : nullptr;
-  // Prevent LazyValueInfo from using the DominatorTree as LowerSwitch does not
-  // preserve it and it becomes stale (when available) pretty much immediately.
-  // Currently the DominatorTree is only used by LowerSwitch indirectly via LVI
-  // and computeKnownBits to refine isValidAssumeForContext's results. Given
-  // that the latter can handle some of the simple cases w/o a DominatorTree,
-  // it's easier to refrain from using the tree than to keep it up to date.
-  LVI->disableDT();
 
   bool Changed = false;
   SmallPtrSet<BasicBlock*, 8> DeleteList;

diff --git a/llvm/test/Analysis/LazyValueAnalysis/invalidation.ll b/llvm/test/Analysis/LazyValueAnalysis/invalidation.ll
@@ -12,18 +12,6 @@
 ; CHECK-INVALIDATE: Invalidating analysis: LazyValueAnalysis
 ; CHECK-INVALIDATE: Running pass: RequireAnalysisPass
 ; CHECK-INVALIDATE: Running analysis: LazyValueAnalysis
-;
-; Check DomTree specifically.
-; RUN: opt -disable-output -disable-verify -debug-pass-manager %s 2>&1 \
-; RUN:     -passes='require<domtree>,require<lazy-value-info>,invalidate<domtree>,require<lazy-value-info>' \
-; RUN:     | FileCheck %s --check-prefix=CHECK-DT-INVALIDATE
-; CHECK-DT-INVALIDATE: Running pass: RequireAnalysisPass
-; CHECK-DT-INVALIDATE: Running analysis: LazyValueAnalysis
-; CHECK-DT-INVALIDATE: Running pass: InvalidateAnalysisPass
-; CHECK-DT-INVALIDATE: Invalidating analysis: DominatorTreeAnalysis
-; CHECK-DT-INVALIDATE: Invalidating analysis: LazyValueAnalysis
-; CHECK-AC-INVALIDATE: Running pass: RequireAnalysisPass
-; CHECK-DT-INVALIDATE: Running analysis: LazyValueAnalysis
 
 target triple = "x86_64-unknown-linux-gnu"