diff --git a/sdrgui/gui/valuedial.cpp b/sdrgui/gui/valuedial.cpp
index cf1f0e1a5..affd40088 100644
--- a/sdrgui/gui/valuedial.cpp
+++ b/sdrgui/gui/valuedial.cpp
@@ -21,6 +21,7 @@
 #include <QMouseEvent>
 #include <QPainter>
 #include <QWheelEvent>
+#include <cstdlib>
 
 #include "gui/valuedial.h"