diff --git a/accessible/src/atk/Makefile.in b/accessible/src/atk/Makefile.in
index 71ce0db24eb..d02379d297a 100644
--- a/accessible/src/atk/Makefile.in
+++ b/accessible/src/atk/Makefile.in
@@ -18,8 +18,10 @@ FORCE_STATIC_LIB = 1
 
 include $(topsrcdir)/config/rules.mk
 
-CFLAGS  	+= $(MOZ_GTK2_CFLAGS)
-CXXFLAGS  += $(MOZ_GTK2_CFLAGS)
+ifdef MOZ_ENABLE_GTK
+CFLAGS      += $(TK_CFLAGS)
+CXXFLAGS    += $(TK_CFLAGS)
+endif
 
 ifdef MOZ_ENABLE_DBUS
 CXXFLAGS += $(MOZ_DBUS_CFLAGS)
diff --git a/accessible/src/base/Makefile.in b/accessible/src/base/Makefile.in
index 39f108a3dae..4faa8fcfdc7 100644
--- a/accessible/src/base/Makefile.in
+++ b/accessible/src/base/Makefile.in
@@ -28,9 +28,11 @@ LOCAL_INCLUDES += \
   -I$(srcdir)/../../../layout/svg \
   -I$(srcdir)/../../../layout/xul/base/src \
   -I$(srcdir)/../../../layout/xul/tree/ \
+  -I$(srcdir)/../../../ipc/chromium/src \
   $(NULL)
 
-ifeq ($(MOZ_WIDGET_TOOLKIT),gtk2)
+ifdef MOZ_ENABLE_GTK
+CXXFLAGS        += $(MOZ_CAIRO_CFLAGS)
 LOCAL_INCLUDES += \
   -I$(srcdir)/../atk \
   $(NULL)
diff --git a/accessible/src/generic/Makefile.in b/accessible/src/generic/Makefile.in
index 34021a5bbf9..1eb54477968 100644
--- a/accessible/src/generic/Makefile.in
+++ b/accessible/src/generic/Makefile.in
@@ -28,7 +28,7 @@ LOCAL_INCLUDES = \
   -I$(srcdir)/../../../layout/xul/base/src \
   $(NULL)
 
-ifeq ($(MOZ_WIDGET_TOOLKIT),gtk2)
+ifdef MOZ_ENABLE_GTK
 LOCAL_INCLUDES += \
   -I$(srcdir)/../atk \
   $(NULL)
diff --git a/accessible/src/html/Makefile.in b/accessible/src/html/Makefile.in
index b7fe6b81f81..afecab7be94 100644
--- a/accessible/src/html/Makefile.in
+++ b/accessible/src/html/Makefile.in
@@ -29,7 +29,7 @@ LOCAL_INCLUDES = \
   -I$(srcdir)/../../../layout/xul/base/src \
   $(NULL)
 
-ifeq ($(MOZ_WIDGET_TOOLKIT),gtk2)
+ifdef MOZ_ENABLE_GTK
 LOCAL_INCLUDES += \
   -I$(srcdir)/../atk \
   $(NULL)
diff --git a/accessible/src/moz.build b/accessible/src/moz.build
index 458d11b129f..6e5f4d51d3a 100644
--- a/accessible/src/moz.build
+++ b/accessible/src/moz.build
@@ -6,7 +6,7 @@
 
 toolkit = CONFIG['MOZ_WIDGET_TOOLKIT']
 
-if toolkit == 'gtk2':
+if CONFIG['MOZ_ENABLE_GTK']:
     DIRS += ['atk']
 elif toolkit == 'windows':
     DIRS += ['windows']
diff --git a/accessible/src/xpcom/Makefile.in b/accessible/src/xpcom/Makefile.in
index 06f1310f602..f8d9979d652 100644
--- a/accessible/src/xpcom/Makefile.in
+++ b/accessible/src/xpcom/Makefile.in
@@ -25,7 +25,7 @@ LOCAL_INCLUDES = \
   -I$(srcdir)/../generic \
   $(NULL)
 
-ifeq ($(MOZ_WIDGET_TOOLKIT),gtk2)
+ifdef MOZ_ENABLE_GTK
 LOCAL_INCLUDES += \
   -I$(srcdir)/../atk \
   $(NULL)
diff --git a/accessible/src/xul/Makefile.in b/accessible/src/xul/Makefile.in
index 4487545195b..507f5c4f698 100644
--- a/accessible/src/xul/Makefile.in
+++ b/accessible/src/xul/Makefile.in
@@ -29,7 +29,7 @@ LOCAL_INCLUDES = \
   -I$(srcdir)/../../../layout/xul/tree// \
   $(NULL)
 
-ifeq ($(MOZ_WIDGET_TOOLKIT),gtk2)
+ifdef MOZ_ENABLE_GTK
 LOCAL_INCLUDES += \
   -I$(srcdir)/../atk \
   $(NULL)
diff --git a/toolkit/components/remote/moz.build b/toolkit/components/remote/moz.build
index 2d28df54ef9..d99e9ea7ef1 100644
--- a/toolkit/components/remote/moz.build
+++ b/toolkit/components/remote/moz.build
@@ -16,7 +16,7 @@ CPP_SOURCES += [
     'nsXRemoteService.cpp',
 ]
 
-if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gtk2':
+if CONFIG['MOZ_ENABLE_GTK']:
     CPP_SOURCES += [
         'nsGTKRemoteService.cpp',
     ]
diff --git a/toolkit/crashreporter/client/Makefile.in b/toolkit/crashreporter/client/Makefile.in
index 802c0b6bcb8..06716e0446f 100644
--- a/toolkit/crashreporter/client/Makefile.in
+++ b/toolkit/crashreporter/client/Makefile.in
@@ -49,7 +49,7 @@ LIBS += \
 LOCAL_INCLUDES += -I$(srcdir) -I$(srcdir)/../google-breakpad/src/common/mac/
 endif
 
-ifeq ($(MOZ_WIDGET_TOOLKIT),gtk2)
+ifdef MOZ_WIDGET_GTK
 
 ifdef MOZ_PLATFORM_MAEMO
 # Maemo's libcurl doesn't ship with a set of CA certificates,
@@ -64,8 +64,8 @@ LIBS += \
   $(DEPTH)/toolkit/crashreporter/google-breakpad/src/common/linux/$(LIB_PREFIX)breakpad_linux_common_s.$(LIB_SUFFIX) \
   $(NULL)
 LOCAL_INCLUDES += -I$(srcdir)
-OS_CXXFLAGS += $(MOZ_GTK2_CFLAGS) $(MOZ_GTHREAD_CFLAGS)
-OS_LIBS += $(MOZ_GTK2_LIBS) $(MOZ_GTHREAD_LIBS)
+OS_CXXFLAGS += $(TK_CFLAGS) $(MOZ_GTHREAD_CFLAGS)
+OS_LIBS += $(TK_LIBS) $(MOZ_GTHREAD_LIBS)
 endif
 
 ifeq ($(OS_ARCH),SunOS)
diff --git a/toolkit/crashreporter/client/moz.build b/toolkit/crashreporter/client/moz.build
index 5c6ab1ca17e..cff50bd77f9 100644
--- a/toolkit/crashreporter/client/moz.build
+++ b/toolkit/crashreporter/client/moz.build
@@ -9,7 +9,7 @@ MODULE = 'crashreporter'
 if CONFIG['OS_TARGET'] != 'Android':
     PROGRAM = 'crashreporter'
 # The xpcshell test case here verifies that the CA certificate list
-if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gtk2' and CONFIG['MOZ_PLATFORM_MAEMO']:
+if CONFIG['MOZ_ENABLE_GTK'] and CONFIG['MOZ_PLATFORM_MAEMO']:
     XPCSHELL_TESTS_MANIFESTS += ['maemo-unit/xpcshell.ini']
 
 CPP_SOURCES += [
@@ -30,7 +30,7 @@ elif CONFIG['OS_ARCH'] == 'SunOS':
         'crashreporter_unix.cpp',
     ]
 
-if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gtk2':
+if CONFIG['MOZ_ENABLE_GTK']:
     CPP_SOURCES += [
         'crashreporter_gtk_common.cpp',
         'crashreporter_unix_common.cpp',
diff --git a/toolkit/library/Makefile.in b/toolkit/library/Makefile.in
index faf5478f44c..49d85ff5e54 100644
--- a/toolkit/library/Makefile.in
+++ b/toolkit/library/Makefile.in
@@ -186,7 +186,7 @@ COMPONENT_LIBS += \
   $(NULL)
 
 ifdef MOZ_XUL
-ifdef MOZ_ENABLE_GTK2
+ifdef MOZ_ENABLE_GTK
 COMPONENT_LIBS += \
   unixproxy \
   $(NULL)
@@ -269,6 +269,10 @@ COMPONENT_LIBS += \
 	$(NULL)
 endif
 
+ifdef MOZ_ENABLE_GTK3
+COMPONENT_LIBS += widget_gtk3
+endif
+
 ifdef MOZ_ENABLE_GTK2
 COMPONENT_LIBS += widget_gtk2
 endif
@@ -280,7 +284,7 @@ endif
 endif
 
 # Platform-specific icon channel stuff - supported mostly-everywhere
-ifneq (,$(filter windows os2 mac cocoa gtk2 qt android,$(MOZ_WIDGET_TOOLKIT)))
+ifneq (,$(filter windows os2 mac cocoa gtk2 gtk3 qt android,$(MOZ_WIDGET_TOOLKIT)))
 DEFINES += -DICON_DECODER
 COMPONENT_LIBS += imgicon
 endif
@@ -530,8 +534,9 @@ ifdef MOZ_ENABLE_DBUS
 EXTRA_DSO_LDOPTS += $(MOZ_DBUS_GLIB_LIBS)
 endif
 
-ifeq (gtk2,$(MOZ_WIDGET_TOOLKIT))
-EXTRA_DSO_LDOPTS += $(XLDFLAGS) $(XLIBS) $(XEXT_LIBS) $(XCOMPOSITE_LIBS) $(MOZ_PANGO_LIBS) $(MOZ_GTK2_LIBS) $(XT_LIBS) -lgthread-2.0
+ifdef MOZ_WIDGET_GTK
+EXTRA_DSO_LDOPTS += $(TK_LIBS)
+EXTRA_DSO_LDOPTS += $(XLDFLAGS) $(XLIBS) $(XEXT_LIBS) $(XCOMPOSITE_LIBS) $(MOZ_PANGO_LIBS) $(XT_LIBS) -lgthread-2.0
 EXTRA_DSO_LDOPTS += $(FT2_LIBS)
 endif
 
diff --git a/toolkit/moz.build b/toolkit/moz.build
index 21231e44bfe..5847ff914e7 100644
--- a/toolkit/moz.build
+++ b/toolkit/moz.build
@@ -30,7 +30,7 @@ if CONFIG['MOZ_MAINTENANCE_SERVICE']:
 
 DIRS += ['xre']
 
-if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('gtk2', 'qt'):
+if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('gtk2', 'gtk3', 'qt'):
     PARALLEL_DIRS += ['system/unixproxy']
 elif CONFIG['MOZ_WIDGET_TOOLKIT'] == 'cocoa':
     PARALLEL_DIRS += ['system/osxproxy']
diff --git a/toolkit/mozapps/installer/packager.mk b/toolkit/mozapps/installer/packager.mk
index a63a39e7a75..97f797db68a 100644
--- a/toolkit/mozapps/installer/packager.mk
+++ b/toolkit/mozapps/installer/packager.mk
@@ -16,7 +16,7 @@ else
 ifeq (,$(filter-out SunOS, $(OS_ARCH)))
    MOZ_PKG_FORMAT  = BZ2
 else
-   ifeq (,$(filter-out gtk2 qt, $(MOZ_WIDGET_TOOLKIT)))
+   ifeq (,$(filter-out gtk2 gtk3 qt, $(MOZ_WIDGET_TOOLKIT)))
       MOZ_PKG_FORMAT  = BZ2
    else
       ifeq (android,$(MOZ_WIDGET_TOOLKIT))
diff --git a/toolkit/mozapps/update/updater/Makefile.in b/toolkit/mozapps/update/updater/Makefile.in
index 406b0d69756..669c964bd99 100644
--- a/toolkit/mozapps/update/updater/Makefile.in
+++ b/toolkit/mozapps/update/updater/Makefile.in
@@ -38,7 +38,7 @@ endif
 
 endif
 
-ifneq ($(MOZ_ENABLE_GTK2),)
+ifdef MOZ_WIDGET_GTK
 OS_CXXFLAGS += $(TK_CFLAGS)
 OS_LIBS += $(TK_LIBS)
 endif
@@ -75,7 +75,7 @@ WIN32_EXE_LDFLAGS += -ENTRY:wmainCRTStartup
 WIN32_EXE_LDFLAGS += -DELAYLOAD:wsock32.dll -DELAYLOAD:crypt32.dll
 endif
 
-ifeq ($(MOZ_WIDGET_TOOLKIT),gtk2)
+ifdef MOZ_WIDGET_GTK
 libs:: updater.png
 	$(NSINSTALL) -D $(DIST)/bin/icons
 	$(INSTALL) $(IFLAGS1) $^ $(DIST)/bin/icons
@@ -111,4 +111,3 @@ ifneq (,$(filter nightly aurora nightly-elm nightly-profiling nightly-oak,$(MOZ_
 RCFLAGS += -DMAR_SIGNING_AURORA_NIGHTLY=1
 endif
 endif
-
diff --git a/toolkit/mozapps/update/updater/moz.build b/toolkit/mozapps/update/updater/moz.build
index eb6f72d4588..0a695de48f4 100644
--- a/toolkit/mozapps/update/updater/moz.build
+++ b/toolkit/mozapps/update/updater/moz.build
@@ -21,7 +21,7 @@ if CONFIG['OS_ARCH'] == 'WINNT':
         'win_dirent.cpp',
     ]
 
-if CONFIG['MOZ_ENABLE_GTK2']:
+if CONFIG['MOZ_ENABLE_GTK']:
     have_progressui = 1
     CPP_SOURCES += [
         'progressui_gtk.cpp',
diff --git a/toolkit/system/gnome/Makefile.in b/toolkit/system/gnome/Makefile.in
index d30c4426c85..c1f84a02825 100644
--- a/toolkit/system/gnome/Makefile.in
+++ b/toolkit/system/gnome/Makefile.in
@@ -33,5 +33,10 @@ CXXFLAGS += \
 	$(MOZ_GNOMEVFS_CFLAGS) \
 	$(MOZ_GIO_CFLAGS) \
 	$(GLIB_CFLAGS) \
-	$(MOZ_GTK2_CFLAGS) \
 	$(NULL)
+
+ifdef MOZ_ENABLE_GTK
+CXXFLAGS += \
+	$(TK_CFLAGS) \
+	$(NULL)
+endif
diff --git a/toolkit/xre/Makefile.in b/toolkit/xre/Makefile.in
index 42f06974ad4..28621dc7e52 100644
--- a/toolkit/xre/Makefile.in
+++ b/toolkit/xre/Makefile.in
@@ -146,7 +146,7 @@ LOCAL_INCLUDES += \
 
 CXXFLAGS += $(TK_CFLAGS) $(MOZ_DBUS_CFLAGS) $(MOZ_DBUS_GLIB_CFLAGS)
 
-ifeq ($(MOZ_WIDGET_TOOLKIT),gtk2)
+ifdef MOZ_WIDGET_GTK
 CXXFLAGS += $(MOZ_PANGO_CFLAGS)
 endif
 
diff --git a/toolkit/xre/moz.build b/toolkit/xre/moz.build
index 9d0abb34df8..01df06809dc 100644
--- a/toolkit/xre/moz.build
+++ b/toolkit/xre/moz.build
@@ -42,7 +42,7 @@ elif CONFIG['MOZ_WIDGET_TOOLKIT'] == 'os2':
     CPP_SOURCES += [
         'nsNativeAppSupportOS2.cpp',
     ]
-elif CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gtk2':
+elif CONFIG['MOZ_ENABLE_GTK']:
     CPP_SOURCES += [
         'nsNativeAppSupportUnix.cpp',
     ]
diff --git a/widget/gtk2/Makefile.in b/widget/gtk2/Makefile.in
index 5a0cdc2c37c..870a4cda48d 100644
--- a/widget/gtk2/Makefile.in
+++ b/widget/gtk2/Makefile.in
@@ -10,10 +10,16 @@ VPATH		= @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
+ifdef MOZ_ENABLE_GTK2
+MODULE_NAME	= nsWidgetGtk2Module
 LIBRARY_NAME	= widget_gtk2
+else
+MODULE_NAME	= nsWidgetGtk3Module
+LIBRARY_NAME	= widget_gtk3
+endif
+
 EXPORT_LIBRARY	= 1
 IS_COMPONENT	= 1
-MODULE_NAME	= nsWidgetGtk2Module
 LIBXUL_LIBRARY = 1
 
 NATIVE_THEME_SUPPORT = 1
@@ -32,7 +38,11 @@ endif
 SHARED_LIBRARY_LIBS = ../xpwidgets/libxpwidgets_s.a
 
 ifdef NATIVE_THEME_SUPPORT
+ifdef MOZ_ENABLE_GTK2
 CSRCS		+= gtk2drawing.c
+else
+CSRCS		+= gtk3drawing.c
+endif
 DEFINES		+= -DNATIVE_THEME_SUPPORT
 endif
 
@@ -40,9 +50,12 @@ include $(topsrcdir)/config/config.mk
 include $(topsrcdir)/ipc/chromium/chromium-config.mk
 include $(topsrcdir)/config/rules.mk
 
-CFLAGS          += $(MOZ_GTK2_CFLAGS) $(MOZ_STARTUP_NOTIFICATION_CFLAGS)
+CFLAGS          += $(MOZ_STARTUP_NOTIFICATION_CFLAGS)
 CXXFLAGS        += $(MOZ_CAIRO_CFLAGS) $(MOZ_PIXMAN_CFLAGS) \
-		$(MOZ_GTK2_CFLAGS) $(MOZ_STARTUP_NOTIFICATION_CFLAGS)
+		               $(MOZ_STARTUP_NOTIFICATION_CFLAGS)
+
+CFLAGS          += $(TK_CFLAGS)
+CXXFLAGS        += $(TK_CFLAGS)
 
 ifdef MOZ_PLATFORM_MAEMO
 ifdef MOZ_ENABLE_GCONF
diff --git a/widget/moz.build b/widget/moz.build
index e0abb6c7871..e7f1a9f9cbb 100644
--- a/widget/moz.build
+++ b/widget/moz.build
@@ -10,7 +10,7 @@ toolkit = CONFIG['MOZ_WIDGET_TOOLKIT']
 
 if toolkit in ('os2', 'cocoa', 'qt', 'android', 'gonk'):
     DIRS += [toolkit]
-if toolkit in ('qt', 'android', 'gonk', 'gtk2'):
+if toolkit in ('qt', 'android', 'gonk', 'gtk2', 'gtk3'):
     EXPORTS += ['nsIPrintDialogService.h']
 
 if toolkit == 'windows':
@@ -54,7 +54,7 @@ TEST_TOOL_DIRS += ['tests']
 # multiple implementations of widget can be built on the same
 # source tree.
 #
-if CONFIG['MOZ_ENABLE_GTK2']:
+if CONFIG['MOZ_ENABLE_GTK']:
     DIRS += ['gtk2']
 
     if CONFIG['MOZ_X11']:
diff --git a/widget/xpwidgets/Makefile.in b/widget/xpwidgets/Makefile.in
index 0c8065c4fa4..e149a004f66 100644
--- a/widget/xpwidgets/Makefile.in
+++ b/widget/xpwidgets/Makefile.in
@@ -27,8 +27,18 @@ ifdef MOZ_ENABLE_D3D10_LAYER
 DEFINES		+= -DMOZ_ENABLE_D3D10_LAYER
 endif
 
+ifneq (,$(filter gtk3,$(MOZ_WIDGET_TOOLKIT)))
+# gtk3 shares includes with gtk2
+LOCAL_INCLUDES	+= \
+		-I$(srcdir)/../gtk2 \
+		$(NULL)
+else
+LOCAL_INCLUDES	+= \
+ 		-I$(srcdir)/../$(MOZ_WIDGET_TOOLKIT) \
+		$(NULL)
+endif
+
 LOCAL_INCLUDES	+= \
-		-I$(srcdir)/../$(MOZ_WIDGET_TOOLKIT) \
 		-I$(srcdir)/../shared \
 		-I$(topsrcdir)/layout/base \
 		-I$(topsrcdir)/layout/forms \
diff --git a/widget/xpwidgets/moz.build b/widget/xpwidgets/moz.build
index 85ac69b6698..8a7e0b667c1 100644
--- a/widget/xpwidgets/moz.build
+++ b/widget/xpwidgets/moz.build
@@ -44,13 +44,13 @@ if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('os2', 'cocoa', 'windows'):
         'nsBaseClipboard.cpp',
     ]
 
-if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('qt', 'gtk2', 'os2', 'cocoa', 'windows',
+if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('qt', 'gtk2', 'gtk3', 'os2', 'cocoa', 'windows',
                                     'android', 'gonk'):
     CPP_SOURCES += [
         'nsBaseFilePicker.cpp',
     ]
 
-if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('qt', 'gtk2', 'windows', 'cocoa'):
+if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('qt', 'gtk2', 'gtk3', 'windows', 'cocoa'):
     CPP_SOURCES += [
         'nsNativeTheme.cpp',
     ]
diff --git a/xpcom/base/Makefile.in b/xpcom/base/Makefile.in
index 3a12f9751bf..8a9f5ebe6fe 100644
--- a/xpcom/base/Makefile.in
+++ b/xpcom/base/Makefile.in
@@ -60,8 +60,8 @@ include $(topsrcdir)/config/rules.mk
 
 DEFINES		+= -D_IMPL_NS_COM
 
-ifneq (,$(filter gtk2,$(MOZ_WIDGET_TOOLKIT)))
-CXXFLAGS        += $(MOZ_GTK2_CFLAGS)
+ifdef MOZ_WIDGET_GTK
+CXXFLAGS        += $(TK_CFLAGS)
 endif
 
 LOCAL_INCLUDES += \
diff --git a/xpcom/base/nsSystemInfo.cpp b/xpcom/base/nsSystemInfo.cpp
index 127d234b960..62a1def86ec 100644
--- a/xpcom/base/nsSystemInfo.cpp
+++ b/xpcom/base/nsSystemInfo.cpp
@@ -116,7 +116,7 @@ nsSystemInfo::Init()
     }
 #endif
 
-#ifdef MOZ_WIDGET_GTK2
+#if defined(MOZ_WIDGET_GTK)
     // This must be done here because NSPR can only separate OS's when compiled, not libraries.
     char* gtkver = PR_smprintf("GTK %u.%u.%u", gtk_major_version, gtk_minor_version, gtk_micro_version);
     if (gtkver) {
diff --git a/xpcom/components/Makefile.in b/xpcom/components/Makefile.in
index c76be43b50c..cb056faf4f2 100644
--- a/xpcom/components/Makefile.in
+++ b/xpcom/components/Makefile.in
@@ -32,6 +32,6 @@ include $(topsrcdir)/config/rules.mk
 
 DEFINES	+= -D_IMPL_NS_COM
 
-ifneq (,$(filter gtk2,$(MOZ_WIDGET_TOOLKIT)))
-CXXFLAGS += $(MOZ_GTK2_CFLAGS)
+ifdef MOZ_WIDGET_GTK
+CXXFLAGS        += $(TK_CFLAGS)
 endif
diff --git a/xpcom/components/ManifestParser.cpp b/xpcom/components/ManifestParser.cpp
index 1dc41ea7588..1710292f006 100644
--- a/xpcom/components/ManifestParser.cpp
+++ b/xpcom/components/ManifestParser.cpp
@@ -464,7 +464,7 @@ ParseManifest(NSLocationType type, FileLocation &file, char* buf, bool aChromeOn
                                          majorVersion,
                                          minorVersion);
   }
-#elif defined(MOZ_WIDGET_GTK2)
+#elif defined(MOZ_WIDGET_GTK)
   nsTextFormatter::ssprintf(osVersion, NS_LITERAL_STRING("%ld.%ld").get(),
                                        gtk_major_version,
                                        gtk_minor_version);
diff --git a/xulrunner/app/Makefile.in b/xulrunner/app/Makefile.in
index 261c59b8797..da90000e636 100644
--- a/xulrunner/app/Makefile.in
+++ b/xulrunner/app/Makefile.in
@@ -102,7 +102,7 @@ LDFLAGS += /HEAP:0x40000
 endif
 endif
 
-ifeq ($(MOZ_WIDGET_TOOLKIT),gtk2)
+ifdef MOZ_WIDGET_GTK
 libs::
 	$(INSTALL) $(IFLAGS1) $(DIST)/branding/default16.png $(DIST)/bin/chrome/icons/default
 	$(INSTALL) $(IFLAGS1) $(DIST)/branding/default32.png $(DIST)/bin/chrome/icons/default
@@ -120,7 +120,7 @@ ifeq ($(OS_ARCH),WINNT)
 	cp $(srcdir)/xulrunner.ico   $(DIST)/branding/app.ico
 	cp $(srcdir)/document.ico  $(DIST)/branding/document.ico
 endif
-ifeq ($(MOZ_WIDGET_TOOLKIT),gtk2)
+ifdef MOZ_WIDGET_GTK
 	cp $(srcdir)/default16.png   $(DIST)/branding/default16.png
 	cp $(srcdir)/default32.png   $(DIST)/branding/default32.png
 	cp $(srcdir)/default48.png   $(DIST)/branding/default48.png