diff --git a/widget/gtk/moz.build b/widget/gtk/moz.build
--- a/widget/gtk/moz.build
+++ b/widget/gtk/moz.build
@@ -185,8 +185,7 @@
     ]
     UNIFIED_SOURCES += [
         "AsyncDBus.cpp",
     ]
     CXXFLAGS += CONFIG["MOZ_DBUS_GLIB_CFLAGS"]
+
 CXXFLAGS += ["-Werror=switch"]
-
-REQUIRES_UNIFIED_BUILD = True