diff --git a/lib/Slic3r/GUI/Tab.pm b/lib/Slic3r/GUI/Tab.pm
index ba887907b..7ebc22e11 100644
--- a/lib/Slic3r/GUI/Tab.pm
+++ b/lib/Slic3r/GUI/Tab.pm
@@ -743,7 +743,7 @@ sub _build_extruder_pages {
         # extend options
         foreach my $opt_key ($self->_extruder_options) {
             my $values = $self->{config}->get($opt_key);
-            $values->[$extruder_idx] = $default_config->get_at($opt_key, 0);
+            $values->[$extruder_idx] //= $default_config->get_at($opt_key, 0);
             $self->{config}->set($opt_key, $values)
                 or die "Unable to extend $opt_key";
         }