diff --git a/t/config.t b/t/config.t
index 829ef5f39..d36912301 100644
--- a/t/config.t
+++ b/t/config.t
@@ -1,4 +1,4 @@
-use Test::More tests => 1;
+use Test::More tests => 4;
 use strict;
 use warnings;
 
@@ -15,6 +15,22 @@ use Slic3r::Test;
     my $config = Slic3r::Config->new_from_defaults;
     $config->set('perimeter_extrusion_width', '250%');
     ok $config->validate, 'percent extrusion width is validated';
+
+    my $print = Slic3r::Test::init_print('20mm_cube', config => $config, scale => 2);
+    {
+        my $invalid = $print->apply_config($config);
+        ok !($invalid), 're-applying same config does not invalidate';
+    }
+    $config->set('perimeters', 20);
+    {
+        my $invalid = $print->apply_config($config);
+        ok $invalid, 're-applying with changed perimeters does invalidate previous config';
+    }
+    $config->set('fill_density', '75%');
+    {
+        my $invalid = $print->apply_config($config);
+        ok $invalid, 're-applying with changed fill_density does invalidate previous config';
+    }
 }
 
 __END__