Index: test/tsan/lit.cfg
===================================================================
--- test/tsan/lit.cfg
+++ test/tsan/lit.cfg
@@ -44,7 +44,7 @@
                       [config.target_cflags] +
                       config.debug_info_flags +
                       extra_cflags)
-clang_tsan_cxxflags = config.cxx_mode_flags + clang_tsan_cflags
+clang_tsan_cxxflags = config.cxx_mode_flags + clang_tsan_cflags + ["-std=c++11"]
 # Add additional flags if we're using instrumented libc++.
 # Instrumented libcxx currently not supported on Darwin.
 if config.has_libcxx and config.host_os != 'Darwin':
@@ -54,8 +54,7 @@
   libcxx_incdir = os.path.join(libcxx_path, "include", "c++", "v1")
   libcxx_libdir = os.path.join(libcxx_path, "lib")
   libcxx_so = os.path.join(libcxx_libdir, "libc++.so")
-  clang_tsan_cxxflags += ["-std=c++11",
-                          "-nostdinc++",
+  clang_tsan_cxxflags += ["-nostdinc++",
                           "-I%s" % libcxx_incdir,
                           libcxx_so,
                           "-Wl,-rpath=%s" % libcxx_libdir]