diff --git a/lib/mac/binding.gyp b/lib/mac/binding.gyp
index 5382f4ce5..d70dc675f 100644
--- a/lib/mac/binding.gyp
+++ b/lib/mac/binding.gyp
@@ -7,7 +7,9 @@
       'dependencies': ["<!(node -p \"require('node-addon-api').gyp\")"],
       'cflags!': [ '-fno-exceptions' ],
       'cflags_cc!': [ '-fno-exceptions' ],
+      'cflags+': ['-fvisibility=hidden'],
       'xcode_settings': {
+          'GCC_SYMBOLS_PRIVATE_EXTERN': 'YES', # -fvisibility=hidden
         'GCC_ENABLE_CPP_EXCEPTIONS': 'YES',
         'CLANG_CXX_LIBRARY': 'libc++',
         'MACOSX_DEPLOYMENT_TARGET': '10.7',