diff --git a/content/media/mediasource/SourceBuffer.cpp b/content/media/mediasource/SourceBuffer.cpp
index bc94789347d..58682ce3fe7 100644
--- a/content/media/mediasource/SourceBuffer.cpp
+++ b/content/media/mediasource/SourceBuffer.cpp
@@ -21,6 +21,7 @@
 #include "nsThreadUtils.h"
 #include "prlog.h"
 #include "SubBufferDecoder.h"
+#include "mozilla/Preferences.h"
 
 struct JSContext;
 class JSObject;