diff --git a/src/core/feeddownloader.cpp b/src/core/feeddownloader.cpp
index 763e52d07..5eb49e476 100755
--- a/src/core/feeddownloader.cpp
+++ b/src/core/feeddownloader.cpp
@@ -23,6 +23,7 @@
 #include <QThread>
 #include <QDebug>
 #include <QMetaType>
+#include <QMutex>
 #include <QThreadPool>
 
 
diff --git a/src/core/feeddownloader.h b/src/core/feeddownloader.h
index 16bef8d34..a3386fad4 100755
--- a/src/core/feeddownloader.h
+++ b/src/core/feeddownloader.h
@@ -49,6 +49,8 @@ class FeedDownloadResults {
     QList<QPair<QString,int> > m_updatedFeeds;
 };
 
+class QMutex;
+
 // This class offers means to "update" feeds and "special" categories.
 // NOTE: This class is used within separate thread.
 class FeedDownloader : public QObject {