Index: lib/Driver/ToolChains/MinGW.cpp
===================================================================
--- lib/Driver/ToolChains/MinGW.cpp
+++ lib/Driver/ToolChains/MinGW.cpp
@@ -456,6 +456,10 @@
   switch (GetCXXStdlibType(DriverArgs)) {
   case ToolChain::CST_Libcxx:
     addSystemInclude(DriverArgs, CC1Args,
+                     Base + Arch + llvm::sys::path::get_separator() +
+                         "include" + llvm::sys::path::get_separator() +
+                         "c++" + llvm::sys::path::get_separator() + "v1");
+    addSystemInclude(DriverArgs, CC1Args,
                      Base + "include" + llvm::sys::path::get_separator() +
                          "c++" + llvm::sys::path::get_separator() + "v1");
     break;
Index: test/Driver/mingw.cpp
===================================================================
--- test/Driver/mingw.cpp
+++ test/Driver/mingw.cpp
@@ -3,6 +3,10 @@
 // CHECK_MINGW_CLANG_TREE: "{{.*}}/Inputs/mingw_clang_tree/mingw32{{/|\\\\}}include"
 
 
+// RUN: %clang -target i686-windows-gnu -rtlib=platform -stdlib=libc++ -c -### --sysroot=%S/Inputs/mingw_clang_tree/mingw32 %s 2>&1 | FileCheck -check-prefix=CHECK_MINGW_CLANG_TREE_LIBCXX %s
+// CHECK_MINGW_CLANG_TREE_LIBCXX: "{{.*}}/Inputs/mingw_clang_tree/mingw32{{/|\\\\}}i686-w64-mingw32{{/|\\\\}}include{{/|\\\\}}c++{{/|\\\\}}v1"
+
+
 // RUN: %clang -target i686-pc-windows-gnu -rtlib=platform -stdlib=libstdc++ -c -### --sysroot=%S/Inputs/mingw_mingw_org_tree/mingw %s 2>&1 | FileCheck -check-prefix=CHECK_MINGW_ORG_TREE %s
 // CHECK_MINGW_ORG_TREE: "{{.*}}/Inputs/mingw_mingw_org_tree/mingw{{/|\\\\}}lib{{/|\\\\}}gcc{{/|\\\\}}mingw32{{/|\\\\}}4.8.1{{/|\\\\}}include{{/|\\\\}}c++"
 // CHECK_MINGW_ORG_TREE: "{{.*}}/Inputs/mingw_mingw_org_tree/mingw{{/|\\\\}}lib{{/|\\\\}}gcc{{/|\\\\}}mingw32{{/|\\\\}}4.8.1{{/|\\\\}}include{{/|\\\\}}c++{{/|\\\\}}mingw32"