diff --git a/prefs.js b/prefs.js
index bf60316..9df6a02 100644
--- a/prefs.js
+++ b/prefs.js
@@ -110,7 +110,7 @@ function buildPrefsWidget() {
 
     // Double width previews
     let doubleWidthLabel = new Gtk.Label({
-        label: _("    Use double width previews on sides in 4 column mode"),
+        label: _("     Use double width previews on sides in 4 column mode"),
         visible: true,
         hexpand: true,
         halign: Gtk.Align.START
@@ -123,6 +123,11 @@ function buildPrefsWidget() {
     layout.attach(doubleWidthLabel, 0, row, 1, 1);
     layout.attach(doubleWidthInput, 1, row++, 1, 1);
 
+    previewInput.connect('state-set', function(widget, state) {
+        doubleWidthLabel.set_sensitive(state);
+        doubleWidthInput.set_sensitive(state);
+    });
+
     // Debug setting
     let debugLabel = new Gtk.Label({
         label: _("Turn on debugging"),