diff --git a/clang-tools-extra/clang-tidy/ClangTidyModule.h b/clang-tools-extra/clang-tidy/ClangTidyModule.h
--- a/clang-tools-extra/clang-tidy/ClangTidyModule.h
+++ b/clang-tools-extra/clang-tidy/ClangTidyModule.h
@@ -69,7 +69,7 @@
   std::vector<std::unique_ptr<ClangTidyCheck>>
   createChecks(ClangTidyContext *Context);
 
-  typedef std::map<std::string, CheckFactory> FactoryMap;
+  typedef llvm::StringMap<CheckFactory> FactoryMap;
   FactoryMap::const_iterator begin() const { return Factories.begin(); }
   FactoryMap::const_iterator end() const { return Factories.end(); }
   bool empty() const { return Factories.empty(); }
diff --git a/clang-tools-extra/clang-tidy/ClangTidyModule.cpp b/clang-tools-extra/clang-tidy/ClangTidyModule.cpp
--- a/clang-tools-extra/clang-tidy/ClangTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/ClangTidyModule.cpp
@@ -18,15 +18,15 @@
 
 void ClangTidyCheckFactories::registerCheckFactory(StringRef Name,
                                                    CheckFactory Factory) {
-  Factories[std::string(Name)] = std::move(Factory);
+  Factories.insert_or_assign(Name, std::move(Factory));
 }
 
 std::vector<std::unique_ptr<ClangTidyCheck>>
 ClangTidyCheckFactories::createChecks(ClangTidyContext *Context) {
   std::vector<std::unique_ptr<ClangTidyCheck>> Checks;
   for (const auto &Factory : Factories) {
-    if (Context->isCheckEnabled(Factory.first))
-      Checks.emplace_back(Factory.second(Factory.first, Context));
+    if (Context->isCheckEnabled(Factory.getKey()))
+      Checks.emplace_back(Factory.getValue()(Factory.getKey(), Context));
   }
   return Checks;
 }