diff --git a/common_gui.cpp b/common_gui.cpp
index 0f38ce8..36b0b9e 100644
--- a/common_gui.cpp
+++ b/common_gui.cpp
@@ -6,6 +6,7 @@
 
 #include "common_gui.h"
 #include "qglobal.h"
+#include <unistd.h>
 
 #ifdef Q_WS_WIN32
 #include "windows.h"