diff --git a/compiler-rt/lib/fuzzer/FuzzerCommand.h b/compiler-rt/lib/fuzzer/FuzzerCommand.h
--- a/compiler-rt/lib/fuzzer/FuzzerCommand.h
+++ b/compiler-rt/lib/fuzzer/FuzzerCommand.h
@@ -139,7 +139,7 @@
   // be the equivalent command line.
   std::string toString() const {
     std::stringstream SS;
-    for (auto &arg : getArguments())
+    for (const auto &arg : getArguments())
       SS << arg << " ";
     if (hasOutputFile())
       SS << ">" << getOutputFile() << " ";
diff --git a/compiler-rt/lib/fuzzer/FuzzerDataFlowTrace.cpp b/compiler-rt/lib/fuzzer/FuzzerDataFlowTrace.cpp
--- a/compiler-rt/lib/fuzzer/FuzzerDataFlowTrace.cpp
+++ b/compiler-rt/lib/fuzzer/FuzzerDataFlowTrace.cpp
@@ -88,7 +88,7 @@
 //   * a function with a less frequently executed code gets bigger weight.
 std::vector<double> BlockCoverage::FunctionWeights(size_t NumFunctions) const {
   std::vector<double> Res(NumFunctions);
-  for (auto &It : Functions) {
+  for (const auto &It : Functions) {
     auto FunctionID = It.first;
     auto Counters = It.second;
     assert(FunctionID < NumFunctions);
diff --git a/compiler-rt/lib/fuzzer/FuzzerInternal.h b/compiler-rt/lib/fuzzer/FuzzerInternal.h
--- a/compiler-rt/lib/fuzzer/FuzzerInternal.h
+++ b/compiler-rt/lib/fuzzer/FuzzerInternal.h
@@ -32,7 +32,7 @@
 class Fuzzer {
 public:
   Fuzzer(UserCallback CB, InputCorpus &Corpus, MutationDispatcher &MD,
-         FuzzingOptions &Options);
+         const FuzzingOptions &Options);
   ~Fuzzer();
   void Loop(std::vector<SizedFile> &CorporaFiles);
   void ReadAndExecuteSeedCorpora(std::vector<SizedFile> &CorporaFiles);
diff --git a/compiler-rt/lib/fuzzer/FuzzerLoop.cpp b/compiler-rt/lib/fuzzer/FuzzerLoop.cpp
--- a/compiler-rt/lib/fuzzer/FuzzerLoop.cpp
+++ b/compiler-rt/lib/fuzzer/FuzzerLoop.cpp
@@ -136,7 +136,7 @@
 }
 
 Fuzzer::Fuzzer(UserCallback CB, InputCorpus &Corpus, MutationDispatcher &MD,
-               FuzzingOptions &Options)
+               const FuzzingOptions &Options)
     : CB(CB), Corpus(Corpus), MD(MD), Options(Options) {
   if (EF->__sanitizer_set_death_callback)
     EF->__sanitizer_set_death_callback(StaticDeathCallback);
diff --git a/compiler-rt/lib/fuzzer/FuzzerMutate.cpp b/compiler-rt/lib/fuzzer/FuzzerMutate.cpp
--- a/compiler-rt/lib/fuzzer/FuzzerMutate.cpp
+++ b/compiler-rt/lib/fuzzer/FuzzerMutate.cpp
@@ -521,7 +521,7 @@
 
 std::string MutationDispatcher::MutationSequence() {
   std::string MS;
-  for (auto &M : CurrentMutatorSequence) {
+  for (const auto &M : CurrentMutatorSequence) {
     MS += M.Name;
     MS += "-";
   }