diff --git a/test/libunwind/test/config.py b/test/libunwind/test/config.py
index 183c48f..977f9a0 100644
--- a/test/libunwind/test/config.py
+++ b/test/libunwind/test/config.py
@@ -49,6 +49,8 @@
         super(Configuration, self).configure_compile_flags()
 
     def configure_compile_flags_header_includes(self):
+        self.configure_config_site_header()
+
         libunwind_headers = self.get_lit_conf(
             'libunwind_headers',
             os.path.join(self.libunwind_src_root, 'include'))