--- a/dom/gamepad/moz.build
+++ b/dom/gamepad/moz.build
@@ -53,17 +53,17 @@ if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'coco
 elif CONFIG['MOZ_WIDGET_TOOLKIT'] == 'windows':
     UNIFIED_SOURCES += [
         'windows/WindowsGamepad.cpp'
     ]
 elif CONFIG['MOZ_WIDGET_TOOLKIT'] == 'android':
     UNIFIED_SOURCES += [
         'android/AndroidGamepad.cpp'
     ]
-elif CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gtk3':
+elif CONFIG['OS_ARCH'] == 'Linux':
     UNIFIED_SOURCES += [
         'linux/LinuxGamepad.cpp'
     ]
 else:
     UNIFIED_SOURCES += [
         'fallback/FallbackGamepad.cpp'
     ]