diff --git a/src/CppParser/AST.cpp b/src/CppParser/AST.cpp
index 390126ce..0f0ce331 100644
--- a/src/CppParser/AST.cpp
+++ b/src/CppParser/AST.cpp
@@ -9,14 +9,38 @@
 #include <algorithm>
 #include <string>
 #include <vector>
+#include <llvm/Support/Path.h>
+
+// copy from widenPath ('llvm/lib/Support/Windows/Path.inc')
+static std::string normalizePath(const std::string & File) {
+    llvm::SmallString<2 * 128> Result;
+
+    for (llvm::sys::path::const_iterator I = llvm::sys::path::begin(File),
+        E = llvm::sys::path::end(File);
+        I != E; ++I) {
+        if (I->size() == 1 && *I == ".")
+            continue;
+        if (I->size() == 2 && *I == "..")
+            llvm::sys::path::remove_filename(Result);
+        else
+            llvm::sys::path::append(Result, *I);
+    }
+
+#ifdef _WIN32
+    // Clean up the file path.
+    std::replace(Result.begin(), Result.end(), '/', '\\');
+#endif
+
+    return Result.c_str();
+}
 
 template<typename T>
 static std::vector<T> split(const T & str, const T & delimiters) {
     std::vector<T> v;
-	if (str.length() == 0) {
-		v.push_back(str);
-		return v;
-	}
+    if (str.length() == 0) {
+        v.push_back(str);
+        return v;
+    }
     typename T::size_type start = 0;
     auto pos = str.find_first_of(delimiters, start);
     while(pos != T::npos) {
@@ -626,21 +650,18 @@ ASTContext::ASTContext() {}
 
 TranslationUnit* ASTContext::FindOrCreateModule(std::string File)
 {
-#ifdef _WIN32
-    // Clean up the file path.
-    std::replace(File.begin(), File.end(), '/', '\\');
-#endif
+    auto normalizedFile = normalizePath(File);
 
     auto existingUnit = std::find_if(TranslationUnits.begin(),
         TranslationUnits.end(), [&](TranslationUnit* unit) {
-            return unit && unit->FileName == File;
+            return unit && unit->FileName == normalizedFile;
     });
 
     if (existingUnit != TranslationUnits.end())
         return *existingUnit;
 
     auto unit = new TranslationUnit();
-    unit->FileName = File;
+    unit->FileName = normalizedFile;
     TranslationUnits.push_back(unit);
 
     return unit;