diff --git a/qt/widgets/common/inc/MantidQtWidgets/Common/DropEventHelper.h b/qt/widgets/common/inc/MantidQtWidgets/Common/DropEventHelper.h
index 3fe5aa2aa77837655ed9010dbaac6f0f4ebfd9d3..69e46409123305419b5474f10e42e98560235424 100644
--- a/qt/widgets/common/inc/MantidQtWidgets/Common/DropEventHelper.h
+++ b/qt/widgets/common/inc/MantidQtWidgets/Common/DropEventHelper.h
@@ -11,9 +11,10 @@ namespace MantidWidgets {
 
 namespace DropEventHelper {
 /// Get all filenames from a QDropEvent
-QStringList getFileNames(const QDropEvent *event);
+EXPORT_OPT_MANTIDQT_COMMON QStringList getFileNames(const QDropEvent *event);
 /// Get all python files from q QDropEvent
-QStringList extractPythonFiles(const QDropEvent *event);
+EXPORT_OPT_MANTIDQT_COMMON QStringList
+extractPythonFiles(const QDropEvent *event);
 };
 
 } // namespace MantidWidgets