diff --git a/dom/media/mp3/moz.build b/dom/media/mp3/moz.build
index 596d061f81..838a5a8540 100644
--- a/dom/media/mp3/moz.build
+++ b/dom/media/mp3/moz.build
@@ -9,7 +9,7 @@ EXPORTS += [
     'MP3Demuxer.h',
 ]
 
-UNIFIED_SOURCES += [
+SOURCES += [
     'MP3Decoder.cpp',
     'MP3Demuxer.cpp',
 ]