diff --git a/llvm/test/Transforms/SimplifyCFG/switch-range-to-icmp.ll b/llvm/test/Transforms/SimplifyCFG/switch-range-to-icmp.ll
@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt %s -simplifycfg -S | FileCheck %s
+; RUN: opt %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s
 
 declare i32 @f(i32)
 

diff --git a/llvm/test/Transforms/SimplifyCFG/switch-simplify-crash.ll b/llvm/test/Transforms/SimplifyCFG/switch-simplify-crash.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -simplifycfg -disable-output
+; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -disable-output
 
 define void @NewExtractNames() {
 entry:

diff --git a/llvm/test/Transforms/SimplifyCFG/switch_create-custom-dl.ll b/llvm/test/Transforms/SimplifyCFG/switch_create-custom-dl.ll
@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -S -simplifycfg < %s | FileCheck %s
+; RUN: opt -S -simplifycfg -simplifycfg-require-and-preserve-domtree=1 < %s | FileCheck %s
 target datalayout="p:40:64:64:32"
 
 declare void @foo1()

diff --git a/llvm/test/Transforms/SimplifyCFG/switch_create.ll b/llvm/test/Transforms/SimplifyCFG/switch_create.ll
@@ -1,6 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -S -simplifycfg < %s | FileCheck %s
-; RUN: opt -S -data-layout="p:32:32-p1:16:16" -simplifycfg < %s | FileCheck -check-prefix=CHECK -check-prefix=DL %s
+; RUN: opt -S -simplifycfg -simplifycfg-require-and-preserve-domtree=1 < %s | FileCheck %s
+; RUN: opt -S -data-layout="p:32:32-p1:16:16" -simplifycfg -simplifycfg-require-and-preserve-domtree=1 < %s | FileCheck -check-prefix=CHECK -check-prefix=DL %s
 
 declare void @foo1()
 

diff --git a/llvm/test/Transforms/SimplifyCFG/switch_switch_fold.ll b/llvm/test/Transforms/SimplifyCFG/switch_switch_fold.ll
@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt < %s -simplifycfg -S | FileCheck %s
+; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s
 
 ; Test that a switch going to a switch on the same value can be merged.
 ; All three switches in this example can be merged into one big one.

diff --git a/llvm/test/Transforms/SimplifyCFG/switch_thread.ll b/llvm/test/Transforms/SimplifyCFG/switch_thread.ll
@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt < %s -simplifycfg -S | FileCheck %s
+; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s
 
 ; Test that we can thread a simple known condition through switch statements.