diff --git a/libcxx/src/filesystem/operations.cpp b/libcxx/src/filesystem/operations.cpp
--- a/libcxx/src/filesystem/operations.cpp
+++ b/libcxx/src/filesystem/operations.cpp
@@ -534,7 +534,7 @@
   ErrorHandler<path> err("canonical", ec, &orig_p, &cwd);
 
   path p = __do_absolute(orig_p, &cwd, ec);
-#if _POSIX_VERSION >= 200112
+#if defined(_POSIX_VERSION) && _POSIX_VERSION >= 200112
   std::unique_ptr<char, decltype(&::free)>
     hold(::realpath(p.c_str(), nullptr), &::free);
   if (hold.get() == nullptr)
diff --git a/libcxx/src/locale.cpp b/libcxx/src/locale.cpp
--- a/libcxx/src/locale.cpp
+++ b/libcxx/src/locale.cpp
@@ -1149,7 +1149,7 @@
 {
     return _LIBCPP_GET_C_LOCALE->__ctype_toupper;
 }
-#elif __NetBSD__
+#elif defined(__NetBSD__)
 const short*
 ctype<char>::__classic_lower_table() _NOEXCEPT
 {