diff --git a/src/frontends/qt4/qt_helpers.h b/src/frontends/qt4/qt_helpers.h
index bacbfbd931..5e7cae2b07 100644
--- a/src/frontends/qt4/qt_helpers.h
+++ b/src/frontends/qt4/qt_helpers.h
@@ -20,6 +20,7 @@
 
 #include <vector>
 #include <utility>
+#include <boost/assert.hpp>
 
 class QComboBox;
 class QLineEdit;