diff --git a/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp b/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
--- a/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
+++ b/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
@@ -245,6 +245,11 @@
                                        FunctionAnalysisManager &AM) {
   auto &TTI = AM.getResult<TargetIRAnalysis>(F);
   Options.AC = &AM.getResult<AssumptionAnalysis>(F);
+  if (F.hasFnAttribute(Attribute::OptForFuzzing)) {
+    Options.setSimplifyCondBranch(false).setFoldTwoEntryPHINode(false);
+  } else {
+    Options.setSimplifyCondBranch(true).setFoldTwoEntryPHINode(true);
+  }
   if (!simplifyFunctionCFG(F, TTI, Options))
     return PreservedAnalyses::all();
   PreservedAnalyses PA;
diff --git a/llvm/test/Transforms/SimplifyCFG/opt-for-fuzzing.ll b/llvm/test/Transforms/SimplifyCFG/opt-for-fuzzing.ll
--- a/llvm/test/Transforms/SimplifyCFG/opt-for-fuzzing.ll
+++ b/llvm/test/Transforms/SimplifyCFG/opt-for-fuzzing.ll
@@ -1,4 +1,5 @@
 ; RUN: opt < %s -simplifycfg -S | FileCheck %s
+; RUN: opt < %s -passes=simplifycfg -S | FileCheck %s
 
 define i32 @foo(i32 %x) optforfuzzing {
 entry: