diff --git a/webrtc/build/common.gypi b/webrtc/build/common.gypi
index 73dda8dcdf..f313402ed6 100644
--- a/webrtc/build/common.gypi
+++ b/webrtc/build/common.gypi
@@ -312,10 +312,12 @@
          ],
       }],
       ['clang==1', {
-        'cflags!': [
-          # TODO(kjellander): Remove when Chromium's common.gypi enables it.
-          '-Wno-unused-const-variable',
-        ],
+        # TODO(kjellander): Remove when Chromium's common.gypi enables this
+        # warning by default (http://crbug.com/307668).
+        'cflags!': ['-Wno-unused-const-variable',],
+        'xcode_settings': {
+          'WARNING_CFLAGS!': ['-Wno-unused-const-variable',],
+        },
       }],
     ], # conditions
     'direct_dependent_settings': {