diff --git a/gfx/2d/moz.build b/gfx/2d/moz.build
index e945563ecd6..5940bfdb42f 100644
--- a/gfx/2d/moz.build
+++ b/gfx/2d/moz.build
@@ -91,18 +91,13 @@ if CONFIG['MOZ_WIDGET_TOOLKIT'] != 'windows':
 if CONFIG['MOZ_ENABLE_SKIA']:
     UNIFIED_SOURCES += [
         'convolver.cpp',
-    ]
-    SOURCES += [
         'DrawTargetSkia.cpp',
-        'image_operations.cpp', # Uses _USE_MATH_DEFINES
         'PathSkia.cpp',
         'SourceSurfaceSkia.cpp',
     ]
-    if CONFIG['CLANG_CXX']:
-        # Suppress warnings from Skia header files.
-        SOURCES['DrawTargetSkia.cpp'].flags += ['-Wno-implicit-fallthrough']
-        SOURCES['PathSkia.cpp'].flags += ['-Wno-implicit-fallthrough']
-        SOURCES['SourceSurfaceSkia.cpp'].flags += ['-Wno-implicit-fallthrough']
+    SOURCES += [
+        'image_operations.cpp', # Uses _USE_MATH_DEFINES
+    ]
     EXPORTS.mozilla.gfx += [
         'HelpersSkia.h',
         'RefPtrSkia.h',
@@ -148,6 +143,7 @@ UNIFIED_SOURCES += [
     'DrawTargetDual.cpp',
     'DrawTargetRecording.cpp',
     'DrawTargetTiled.cpp',
+    'Factory.cpp',
     'FilterNodeSoftware.cpp',
     'FilterProcessing.cpp',
     'FilterProcessingScalar.cpp',
@@ -170,13 +166,6 @@ UNIFIED_SOURCES += [
     'SourceSurfaceRawData.cpp',
 ]
 
-SOURCES += [
-    'Factory.cpp', # Need to suppress warnings in Skia header files.
-]
-
-if CONFIG['CLANG_CXX']:
-    SOURCES['Factory.cpp'].flags += ['-Wno-implicit-fallthrough']
-
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'cocoa':
     EXPORTS.mozilla.gfx += [
         'QuartzSupport.h',
diff --git a/gfx/gl/moz.build b/gfx/gl/moz.build
index a72c43ab1d4..94b1d588ca4 100644
--- a/gfx/gl/moz.build
+++ b/gfx/gl/moz.build
@@ -80,12 +80,9 @@ if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'windows':
     ]
 if CONFIG['MOZ_ENABLE_SKIA_GPU']:
     EXPORTS += ['SkiaGLGlue.h']
-    SOURCES += [
+    UNIFIED_SOURCES += [
         'SkiaGLGlue.cpp',
     ]
-    if CONFIG['CLANG_CXX']:
-        # Suppress warnings from Skia header files.
-        SOURCES['SkiaGLGlue.cpp'].flags += ['-Wno-implicit-fallthrough']
 
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gonk':
     UNIFIED_SOURCES += ['SharedSurfaceGralloc.cpp']
diff --git a/gfx/thebes/moz.build b/gfx/thebes/moz.build
index 210deb7911b..0f0d555e21a 100644
--- a/gfx/thebes/moz.build
+++ b/gfx/thebes/moz.build
@@ -307,7 +307,3 @@ if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('gtk2', 'gtk3', 'qt'):
 LOCAL_INCLUDES += CONFIG['SKIA_INCLUDES']
 
 DEFINES['GRAPHITE2_STATIC'] = True
-
-if CONFIG['CLANG_CXX']:
-    # Suppress warnings from Skia header files.
-    SOURCES['gfxPlatform.cpp'].flags += ['-Wno-implicit-fallthrough']