diff --git a/libcxx/include/filesystem b/libcxx/include/filesystem
--- a/libcxx/include/filesystem
+++ b/libcxx/include/filesystem
@@ -253,7 +253,7 @@
 #endif
 
 #if defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY)
-# error "The Filesystem library is not supported by this configuration of libc++"
+# error "The Filesystem library is not supported since libc++ has been configured with LIBCXX_ENABLE_FILESYSTEM disabled"
 #endif
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
diff --git a/libcxx/include/locale.h b/libcxx/include/locale.h
--- a/libcxx/include/locale.h
+++ b/libcxx/include/locale.h
@@ -36,7 +36,8 @@
 #include <__config>
 
 #if defined(_LIBCPP_HAS_NO_LOCALIZATION)
-#   error "Localization is not supported by this configuration of libc++"
+#error                                                                                                                 \
+    "The Localization library is not supported since libc++ has been configured with LIBCXX_ENABLE_LOCALIZATION disabled"
 #endif
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)