--- a/media/webrtc/moz.build
+++ b/media/webrtc/moz.build
@@ -88,17 +88,16 @@ if CONFIG['MOZ_WEBRTC_SIGNALING']:
         'signaling/src/sdp/sipcc/sdp_base64.c',
         'signaling/src/sdp/sipcc/sdp_config.c',
         'signaling/src/sdp/sipcc/sdp_main.c',
         'signaling/src/sdp/sipcc/sdp_services_unix.c',
         'signaling/src/sdp/sipcc/sdp_token.c',
         'signaling/src/sdp/sipcc/sdp_utils.c',
     ]
 
-    GYP_DIRS['signaling'].sandbox_vars['ALLOW_COMPILER_WARNINGS'] = True
     GYP_DIRS['signaling'].non_unified_sources += signaling_non_unified_sources
 
     if CONFIG['_MSC_VER']:
         # Avoid warnings from third-party code that we can not modify.
         if CONFIG['CLANG_CL']:
             CXXFLAGS += ['-Wno-invalid-source-encoding']
         else:
             CXXFLAGS += ['-validate-charset-']
@@ -116,13 +115,13 @@ if CONFIG['MOZ_WIDGET_TOOLKIT'] != 'gonk
         GYP_DIRS += ['signalingtest']
         GYP_DIRS['signalingtest'].input = 'signaling/signaling.gyp'
         GYP_DIRS['signalingtest'].variables = gyp_vars.copy()
         GYP_DIRS['signalingtest'].variables.update(
             build_for_test=1,
             moz_webrtc_mediacodec=0,
             build_for_standalone=0
         )
-        GYP_DIRS['signalingtest'].sandbox_vars['ALLOW_COMPILER_WARNINGS'] = True
+
         GYP_DIRS['signalingtest'].non_unified_sources += signaling_non_unified_sources
 
 if CONFIG['ENABLE_TESTS']:
     DIRS += ['signaling/fuzztest']

--- a/media/webrtc/signaling/signaling.gyp
+++ b/media/webrtc/signaling/signaling.gyp
@@ -360,16 +360,21 @@
             'SIP_OS_OSX',
             'OSX',
             '_FORTIFY_SOURCE=2',
           ],
 
           'cflags_mozilla': [
           ],
         }],
+        ['clang == 1', {
+          'cflags_mozilla': [
+            '-Wno-inconsistent-missing-override',
+         ],
+        }],
       ],
     },
   ],
 }
 
 # Local Variables:
 # tab-width:2
 # indent-tabs-mode:nil