diff --git a/config/install/diff.settings.yml b/config/install/diff.settings.yml
index c3e9662..c753262 100644
--- a/config/install/diff.settings.yml
+++ b/config/install/diff.settings.yml
@@ -6,10 +6,10 @@ general_settings:
   layout_plugins:
     classic:
       enabled: true
-      weight: -50
+      weight: 0
     markdown:
       enabled: true
-      weight: -49
+      weight: 1
     single_column:
       enabled: true
-      weight: -48
+      weight: 2
diff --git a/src/DiffLayoutManager.php b/src/DiffLayoutManager.php
index 6ac8217..befb7a4 100644
--- a/src/DiffLayoutManager.php
+++ b/src/DiffLayoutManager.php
@@ -93,7 +93,6 @@ class DiffLayoutManager extends DefaultPluginManager {
    */
   public function getDefaultLayout() {
     $plugins = $this->getPluginOptions();
-    list($plugin) = array_keys($plugins);
-    return $plugin;
+    return reset(array_keys($plugins));
   }
 }
diff --git a/src/Form/GeneralSettingsForm.php b/src/Form/GeneralSettingsForm.php
index 9a48cc9..f12a811 100644
--- a/src/Form/GeneralSettingsForm.php
+++ b/src/Form/GeneralSettingsForm.php
@@ -87,7 +87,7 @@ class GeneralSettingsForm extends ConfigFormBase {
     );
 
     $layout_plugins = $this->diffLayoutManager->getDefinitions();
-    $weight = count($layout_plugins) + 1;
+    $weight = max($layout_plugins) + 1;
     $layout_plugins_order = [];
     foreach ($layout_plugins as $id => $layout_plugin) {
       $layout_plugins_order[$id] = [