diff --git a/llvm_util/llvm_optimizer.cpp b/llvm_util/llvm_optimizer.cpp
index c37e7249d..d8cfb8c35 100644
--- a/llvm_util/llvm_optimizer.cpp
+++ b/llvm_util/llvm_optimizer.cpp
@@ -29,7 +29,7 @@ string optimize_module(llvm::Module &M, string_view optArgs) {
   Triple ModuleTriple(M.getTargetTriple());
   unique_ptr<llvm::TargetMachine> TM;
   if (ModuleTriple.getArch()) {
-    auto ETM = codegen::createTargetMachineForTriple(ModuleTriple.str());
+    auto ETM = codegen::createTargetMachineForTriple(ModuleTriple);
     if (auto E = ETM.takeError())
       return toString(std::move(E));
     TM = std::move(*ETM);