diff --git a/bolt/include/bolt/Core/BinaryContext.h b/bolt/include/bolt/Core/BinaryContext.h
--- a/bolt/include/bolt/Core/BinaryContext.h
+++ b/bolt/include/bolt/Core/BinaryContext.h
@@ -650,11 +650,11 @@
 
   /// Address of the code/function that is executed before any other code in
   /// the binary.
-  Optional<uint64_t> StartFunctionAddress;
+  std::optional<uint64_t> StartFunctionAddress;
 
   /// Address of the code/function that is going to be executed right before
   /// the execution of the binary is completed.
-  Optional<uint64_t> FiniFunctionAddress;
+  std::optional<uint64_t> FiniFunctionAddress;
 
   /// Page alignment used for code layout.
   uint64_t PageAlign{HugePageSize};
diff --git a/bolt/lib/Rewrite/MachORewriteInstance.cpp b/bolt/lib/Rewrite/MachORewriteInstance.cpp
--- a/bolt/lib/Rewrite/MachORewriteInstance.cpp
+++ b/bolt/lib/Rewrite/MachORewriteInstance.cpp
@@ -197,9 +197,9 @@
   return DataInCode;
 }
 
-Optional<uint64_t> readStartAddress(const MachOObjectFile &O) {
-  Optional<uint64_t> StartOffset;
-  Optional<uint64_t> TextVMAddr;
+std::optional<uint64_t> readStartAddress(const MachOObjectFile &O) {
+  std::optional<uint64_t> StartOffset;
+  std::optional<uint64_t> TextVMAddr;
   for (const object::MachOObjectFile::LoadCommandInfo &LC : O.load_commands()) {
     switch (LC.C.cmd) {
     case MachO::LC_MAIN: {
@@ -228,7 +228,7 @@
     }
   }
   return (TextVMAddr && StartOffset)
-             ? Optional<uint64_t>(*TextVMAddr + *StartOffset)
+             ? std::optional<uint64_t>(*TextVMAddr + *StartOffset)
              : std::nullopt;
 }
 
diff --git a/bolt/lib/Rewrite/RewriteInstance.cpp b/bolt/lib/Rewrite/RewriteInstance.cpp
--- a/bolt/lib/Rewrite/RewriteInstance.cpp
+++ b/bolt/lib/Rewrite/RewriteInstance.cpp
@@ -4762,7 +4762,7 @@
     assert(SymbolName && "cannot get symbol name");
 
     auto updateSymbolValue = [&](const StringRef Name,
-                                 Optional<uint64_t> Value = std::nullopt) {
+                                 std::optional<uint64_t> Value = std::nullopt) {
       NewSymbol.st_value = Value ? *Value : getNewValueForSymbol(Name);
       NewSymbol.st_shndx = ELF::SHN_ABS;
       outs() << "BOLT-INFO: setting " << Name << " to 0x"