diff --git a/libreofficekit/qa/gtktiledviewer/gtv-lok-dialog.cxx b/libreofficekit/qa/gtktiledviewer/gtv-lok-dialog.cxx
index bb70a15159d1..a67d3427eae5 100644
--- a/libreofficekit/qa/gtktiledviewer/gtv-lok-dialog.cxx
+++ b/libreofficekit/qa/gtktiledviewer/gtv-lok-dialog.cxx
@@ -11,6 +11,7 @@
 #include <gdk/gdkkeysyms.h>
 
 #include <iostream>
+#include <sstream>
 
 #include <LibreOfficeKit/LibreOfficeKitGtk.h>
 #include <LibreOfficeKit/LibreOfficeKitEnums.h>