diff --git a/tools/v8_gypfiles/v8.gyp b/tools/v8_gypfiles/v8.gyp
index 9acad07d966a354..19e490167fc0dce 100644
--- a/tools/v8_gypfiles/v8.gyp
+++ b/tools/v8_gypfiles/v8.gyp
@@ -41,6 +41,14 @@
         'AdditionalOptions': ['/utf-8']
       }
     },
+    # Hide symbols that are not explicitly exported with V8_EXPORT.
+    'cflags': ['-fvisibility=hidden'],
+    'xcode_settings': {
+      'GCC_SYMBOLS_PRIVATE_EXTERN': 'YES',  # -fvisibility=hidden
+    },
+    'defines': [
+      'BUILDING_V8_SHARED',  # Make V8_EXPORT visible.
+    ],
   },
   'targets': [
     {