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
@@ -112,11 +112,6 @@
             return check_value(val, env_var)
         return check_value(conf_val, name)
 
-    def get_modules_enabled(self):
-        return self.get_lit_bool('enable_modules',
-                                default=False,
-                                env_var='LIBCXX_ENABLE_MODULES')
-
     def make_static_lib_name(self, name):
         """Return the full filename for the specified library name"""
         if self.is_windows:
@@ -666,16 +661,14 @@
         # FIXME: This is a hack that should be fixed using module maps (or something)
         # If modules are enabled then we have to lift all of the definitions
         # in __config_site onto the command line.
-        modules_enabled = self.get_modules_enabled()
         self.cxx.compile_flags += ['-Wno-macro-redefined']
         # Transform each macro name into the feature name used in the tests.
         # Ex. _LIBCPP_HAS_NO_THREADS -> libcpp-has-no-threads
         for m in feature_macros:
-            if modules_enabled:
-                define = '-D%s' % m
-                if feature_macros[m]:
-                    define += '=%s' % (feature_macros[m])
-                self.cxx.compile_flags += [define]
+            define = '-D%s' % m
+            if feature_macros[m]:
+                define += '=%s' % (feature_macros[m])
+            self.cxx.compile_flags += [define]
             if m == '_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS' or \
                m == '_LIBCPP_HIDE_FROM_ABI_PER_TU_BY_DEFAULT':
                 continue
@@ -1007,10 +1000,6 @@
         if platform.system() != 'Darwin':
             modules_flags += ['-Xclang', '-fmodules-local-submodule-visibility']
         supports_modules = self.cxx.hasCompileFlag(modules_flags)
-        enable_modules = self.get_modules_enabled()
-        if enable_modules and not supports_modules:
-            self.lit_config.fatal(
-                '-fmodules is enabled but not supported by the compiler')
         if not supports_modules:
             return
         self.config.available_features.add('modules-support')
@@ -1022,9 +1011,8 @@
         os.makedirs(module_cache)
         self.cxx.modules_flags = modules_flags + \
             ['-fmodules-cache-path=' + module_cache]
-        if enable_modules:
-            self.config.available_features.add('-fmodules')
-            self.cxx.useModules()
+        self.config.available_features.add('-fmodules')
+        self.cxx.useModules()
 
     def configure_substitutions(self):
         sub = self.config.substitutions