diff --git a/libcxx/utils/libcxx/test/features.py b/libcxx/utils/libcxx/test/features.py
--- a/libcxx/utils/libcxx/test/features.py
+++ b/libcxx/utils/libcxx/test/features.py
@@ -150,6 +150,7 @@
 DEFAULT_FEATURES += [
   Feature(name='darwin', when=lambda cfg: '__APPLE__' in compilerMacros(cfg)),
   Feature(name='windows', when=lambda cfg: '_WIN32' in compilerMacros(cfg)),
+  Feature(name='windows-dll', when=lambda cfg: '_WIN32' in compilerMacros(cfg) and cfg.enable_shared),
   Feature(name='linux', when=lambda cfg: '__linux__' in compilerMacros(cfg)),
   Feature(name='netbsd', when=lambda cfg: '__NetBSD__' in compilerMacros(cfg)),
   Feature(name='freebsd', when=lambda cfg: '__FreeBSD__' in compilerMacros(cfg))