Index: cfe/trunk/lib/Lex/PPDirectives.cpp
===================================================================
--- cfe/trunk/lib/Lex/PPDirectives.cpp
+++ cfe/trunk/lib/Lex/PPDirectives.cpp
@@ -1813,9 +1813,17 @@
           return Filename;
         };
         StringRef TypoCorrectionName = CorrectTypoFilename(Filename);
+        SmallString<128> NormalizedTypoCorrectionPath;
+        if (LangOpts.MSVCCompat) {
+          NormalizedTypoCorrectionPath = TypoCorrectionName.str();
+#ifndef _WIN32
+          llvm::sys::path::native(NormalizedTypoCorrectionPath);
+#endif
+        }
         File = LookupFile(
             FilenameLoc,
-            LangOpts.MSVCCompat ? NormalizedPath.c_str() : TypoCorrectionName,
+            LangOpts.MSVCCompat ? NormalizedTypoCorrectionPath.c_str()
+                                : TypoCorrectionName,
             isAngled, LookupFrom, LookupFromFile, CurDir,
             Callbacks ? &SearchPath : nullptr,
             Callbacks ? &RelativePath : nullptr, &SuggestedModule, &IsMapped);
Index: cfe/trunk/test/Preprocessor/include-likely-typo.c
===================================================================
--- cfe/trunk/test/Preprocessor/include-likely-typo.c
+++ cfe/trunk/test/Preprocessor/include-likely-typo.c
@@ -1,3 +1,4 @@
 // RUN: %clang_cc1 %s -verify
+// RUN: %clang_cc1 -fms-compatibility %s -verify
 
 #include "<empty_file_to_include.h>" // expected-error {{'<empty_file_to_include.h>' file not found, did you mean 'empty_file_to_include.h'?}}