--- a/dom/html/HTMLMediaElement.cpp
+++ b/dom/html/HTMLMediaElement.cpp
@@ -9,16 +9,17 @@
 #include "mozilla/dom/HTMLSourceElement.h"
 #include "mozilla/dom/ElementInlines.h"
 #include "mozilla/dom/Promise.h"
 #include "mozilla/ArrayUtils.h"
 #include "mozilla/MathAlgorithms.h"
 #include "mozilla/AsyncEventDispatcher.h"
 #include "mozilla/dom/MediaEncryptedEvent.h"
 #include "mozilla/EMEUtils.h"
+#include "mozilla/Sprintf.h"
 
 #include "base/basictypes.h"
 #include "nsIDOMHTMLMediaElement.h"
 #include "nsIDOMHTMLSourceElement.h"
 #include "TimeRanges.h"
 #include "nsGenericHTMLElement.h"
 #include "nsAttrValueInlines.h"
 #include "nsDocShellLoadTypes.h"