diff --git a/toolkit/xre/moz.build b/toolkit/xre/moz.build
--- a/toolkit/xre/moz.build
+++ b/toolkit/xre/moz.build
@@ -116,17 +116,17 @@ UNIFIED_SOURCES += [
 # they pull in OS X system headers.
 # nsEmbedFunctions.cpp cannot be built in unified mode because it pulls in X11 headers.
 SOURCES += [
     'nsAppRunner.cpp',
     'nsEmbedFunctions.cpp',
     'ProfileReset.cpp',
 ]
 
-if CONFIG['MOZ_GL_DEFAULT_PROVIDER'] == 'GLX':
+if CONFIG['MOZ_X11']:
     UNIFIED_SOURCES += [
         'glxtest.cpp',
     ]
 
 if CONFIG['MOZ_INSTRUMENT_EVENT_LOOP']:
     UNIFIED_SOURCES += [
         'EventTracer.cpp',
     ]
@@ -142,17 +142,17 @@ if CONFIG['MOZ_PDF_PRINTING']:
     LOCAL_INCLUDES += [
         '../components/printingui',
     ]
 
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
-if CONFIG['MOZ_GL_DEFAULT_PROVIDER'] == 'GLX':
+if CONFIG['MOZ_X11']:
     DEFINES['USE_GLX_TEST'] = True
 
 for var in ('MOZ_APP_NAME', 'MOZ_APP_BASENAME', 'MOZ_APP_DISPLAYNAME',
             'MOZ_APP_VERSION', 'OS_TARGET', 'MOZ_WIDGET_TOOLKIT'):
     DEFINES[var] = '"%s"' % CONFIG[var]
 
 if CONFIG['MOZ_UPDATER'] and CONFIG['MOZ_WIDGET_TOOLKIT'] != 'android':
     DEFINES['MOZ_UPDATER'] = True