diff --git a/lib/Frontend/InitHeaderSearch.cpp b/lib/Frontend/InitHeaderSearch.cpp
index d2dd0ad..412b707 100644
--- a/lib/Frontend/InitHeaderSearch.cpp
+++ b/lib/Frontend/InitHeaderSearch.cpp
@@ -98,11 +98,11 @@
     AddPath(at, Angled, false, true, false);
 }
 
-void InitHeaderSearch::AddGnuCPlusPlusIncludePaths(std::string base,
-                                                   std::string arch) {
-    AddPath(base, System, true, false, false);
-    AddPath(base + "/" + arch, System, true, false, false);
-    AddPath(base + "/backward", System, true, false, false);
+void InitHeaderSearch::AddGnuCPlusPlusIncludePaths(const std::string &Base,
+                                                  const char *Arch) {
+    AddPath(Base, System, true, false, false);
+    AddPath(Base + "/" + Arch, System, true, false, false);
+    AddPath(Base + "/backward", System, true, false, false);
 }
 
 #if defined(LLVM_ON_WIN32)