Index: libcxx/src/filesystem/operations.cpp
===================================================================
--- libcxx/src/filesystem/operations.cpp
+++ libcxx/src/filesystem/operations.cpp
@@ -1594,8 +1594,13 @@
   for (auto& ep : env_paths)
     if ((ret = getenv(ep)))
       break;
-  if (ret == nullptr)
+  if (ret == nullptr) {
+#if defined(_LIBCPP_WIN32API)
+    ret = "c:\\windows";
+#else
     ret = "/tmp";
+#endif
+  }
 
   path p(ret);
   error_code m_ec;