diff --git a/src/multimedia/audio/qsamplecache_p.h b/src/multimedia/audio/qsamplecache_p.h
index a5eb281b..1dc9371d 100644
--- a/src/multimedia/audio/qsamplecache_p.h
+++ b/src/multimedia/audio/qsamplecache_p.h
@@ -68,7 +68,7 @@ QT_BEGIN_NAMESPACE
 
 QT_MODULE(Multimedia)
 
-
+class QIODevice;
 class QNetworkAccessManager;
 class QSampleCache;
 class QWaveDecoder;