diff --git a/libcxx/test/std/input.output/filesystems/lit.local.cfg b/libcxx/test/std/input.output/filesystems/lit.local.cfg
--- a/libcxx/test/std/input.output/filesystems/lit.local.cfg
+++ b/libcxx/test/std/input.output/filesystems/lit.local.cfg
@@ -1,5 +1,18 @@
+import copy
+import os
+import sys
+
 # Disable all of the filesystem tests if the dylib under test doesn't support them.
 if 'dylib-has-no-filesystem' in config.available_features:
   config.unsupported = True
 if 'c++filesystem-disabled' in config.available_features:
   config.unsupported = True
+
+config.test_format.cxx = copy.deepcopy(config.test_format.cxx)
+
+inputs = os.path.join(os.path.dirname(__file__), 'Inputs', 'static_test_env')
+config.test_format.cxx.compile_flags += ['-DLIBCXX_FILESYSTEM_STATIC_TEST_ROOT="{}"'.format(inputs)]
+
+dynamic_helper = os.path.join(config.test_source_root, 'support', 'filesystem_dynamic_test_helper.py')
+assert os.path.isfile(dynamic_helper)
+config.test_format.cxx.compile_flags += ['-DLIBCXX_FILESYSTEM_DYNAMIC_TEST_HELPER="{} {}"'.format(sys.executable, dynamic_helper)]
diff --git a/libcxx/utils/libcxx/test/config.py b/libcxx/utils/libcxx/test/config.py
--- a/libcxx/utils/libcxx/test/config.py
+++ b/libcxx/utils/libcxx/test/config.py
@@ -140,7 +140,6 @@
         self.configure_execute_external()
         self.configure_ccache()
         self.configure_compile_flags()
-        self.configure_filesystem_compile_flags()
         self.configure_link_flags()
         self.configure_env()
         self.configure_color_diagnostics()
@@ -724,21 +723,6 @@
           self.config.available_features.add('libcpp-abi-unstable')
           self.cxx.compile_flags += ['-D_LIBCPP_ABI_UNSTABLE']
 
-    def configure_filesystem_compile_flags(self):
-        static_env = os.path.join(self.libcxx_src_root, 'test', 'std',
-                                  'input.output', 'filesystems', 'Inputs', 'static_test_env')
-        static_env = os.path.realpath(static_env)
-        assert os.path.isdir(static_env)
-        self.cxx.compile_flags += ['-DLIBCXX_FILESYSTEM_STATIC_TEST_ROOT="%s"' % static_env]
-
-        dynamic_helper = os.path.join(self.libcxx_src_root, 'test', 'support',
-                                      'filesystem_dynamic_test_helper.py')
-        assert os.path.isfile(dynamic_helper)
-
-        self.cxx.compile_flags += ['-DLIBCXX_FILESYSTEM_DYNAMIC_TEST_HELPER="%s %s"'
-                                   % (sys.executable, dynamic_helper)]
-
-
     def configure_link_flags(self):
         # Configure library path
         self.configure_link_flags_cxx_library_path()