diff --git a/clang/lib/Frontend/ModuleDependencyCollector.cpp b/clang/lib/Frontend/ModuleDependencyCollector.cpp
index e3e2685..d23f988 100644
--- a/clang/lib/Frontend/ModuleDependencyCollector.cpp
+++ b/clang/lib/Frontend/ModuleDependencyCollector.cpp
@@ -11,6 +11,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "clang/Basic/CharInfo.h"
 #include "clang/Frontend/Utils.h"
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Serialization/ASTReader.h"
@@ -91,7 +92,7 @@
   // sensitive in the absense of realpath, since this is what the VFSWriter
   // already expects when sensitivity isn't setup.
   for (auto &C : Path)
-    UpperDest.push_back(::toupper(C));
+    UpperDest.push_back(toUppercase(C));
   if (real_path(UpperDest, RealDest) && Path.equals(RealDest))
     return false;
   return true;