diff --git a/dom/filehandle/moz.build b/dom/filehandle/moz.build
index b4e3b64c05..37e5c22a71 100644
--- a/dom/filehandle/moz.build
+++ b/dom/filehandle/moz.build
@@ -18,7 +18,7 @@ EXPORTS.mozilla.dom += [
     'MutableFileBase.h',
 ]
 
-UNIFIED_SOURCES += [
+SOURCES += [
     'ActorsChild.cpp',
     'ActorsParent.cpp',
     'FileHandleBase.cpp',