diff --git a/gramps/gui/plug/export/_exportassistant.py b/gramps/gui/plug/export/_exportassistant.py
index 4125b5b05..227cda1a0 100644
--- a/gramps/gui/plug/export/_exportassistant.py
+++ b/gramps/gui/plug/export/_exportassistant.py
@@ -119,7 +119,8 @@ class ExportAssistant(Gtk.Assistant, ManagedWindow) :
 
         #set_window is present in both parent classes
         ManagedWindow.set_window(self, self, None,
-            self.top_title, isWindow=True)        
+            self.top_title, isWindow=True)
+        self.set_modal(True)
 
         #set up callback method for the export plugins
         self.callback = self.pulse_progressbar