diff --git a/libcxx/src/CMakeLists.txt b/libcxx/src/CMakeLists.txt
--- a/libcxx/src/CMakeLists.txt
+++ b/libcxx/src/CMakeLists.txt
@@ -65,6 +65,8 @@
   verbose_abort.cpp
   )
 
+add_definitions("-Wno-user-defined-literals")
+
 if (LIBCXX_ENABLE_DEBUG_MODE OR LIBCXX_ENABLE_BACKWARDS_COMPATIBILITY_DEBUG_MODE_SYMBOLS)
   list(APPEND LIBCXX_SOURCES
     debug.cpp