diff --git a/clapper_src/filechooser.js b/clapper_src/filechooser.js
index f4c51597..84b996fc 100644
--- a/clapper_src/filechooser.js
+++ b/clapper_src/filechooser.js
@@ -7,6 +7,7 @@ class ClapperFileChooser extends Gtk.FileChooserNative
     {
         super._init({
             transient_for: window,
+            modal: true,
         });
 
         let filter = new Gtk.FileFilter({
diff --git a/clapper_src/uridialog.js b/clapper_src/uridialog.js
index d7b78bf3..c224bc9e 100644
--- a/clapper_src/uridialog.js
+++ b/clapper_src/uridialog.js
@@ -9,6 +9,7 @@ class ClapperUriDialog extends Gtk.Dialog
             transient_for: window,
             title: 'Open URI',
             default_width: 460,
+            modal: true,
         });
 
         let box = new Gtk.Box({