eduardo morales alberti
--- a/core/modules/system/src/Plugin/Condition/CurrentThemeCondition.php
+++ b/core/modules/system/src/Plugin/Condition/CurrentThemeCondition.php
   * {@inheritdoc}
   */
  public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
-    $form['theme'] = [
-      '#type' => 'select',
-      '#title' => $this->t('Theme'),
-      '#default_value' => $this->configuration['theme'],
-      '#options' => array_map(function ($theme_info) {
-        return $theme_info->info['name'];
-      }, $this->themeHandler->listInfo()),
+    $form['themes'] = [
+      '#type' => 'checkboxes',
+      '#title' => $this->t('Themes'),
+      '#default_value' => $this->configuration['themes'],
+      '#options' => $this->getAllAvailableThemeOptions(),
+      '#description' => $this->t('Select the themes this condition should evaluate TRUE on. If nothing is checked "Negate the condition" will be ignored and this condition always evaluates to TRUE.'),
--- a/core/modules/system/config/schema/system.schema.yml
+++ b/core/modules/system/config/schema/system.schema.yml
 condition.plugin.current_theme:
  type: condition.plugin
  mapping:
-    theme:
-      type: string
-      label: Theme
--- a/core/modules/system/src/Plugin/Condition/CurrentThemeCondition.php
+++ b/core/modules/system/src/Plugin/Condition/CurrentThemeCondition.php

  /**
   * {@inheritdoc}
   */
  public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
-    $form['theme'] = [
-      '#type' => 'select',
-      '#title' => $this->t('Theme'),
-      '#default_value' => $this->configuration['theme'],
-      '#options' => array_map(function ($theme_info) {
-        return $theme_info->info['name'];
-      }, $this->themeHandler->listInfo()),
+    $form['themes'] = [
+      '#type' => 'checkboxes',
+      '#title' => $this->t('Themes'),
+      '#default_value' => $this->configuration['themes'],
-      '#default_value' => $this->configuration['themes'],
+      '#default_value' => $this->configuration['themes'] ?? ($this->configuration['theme'] ? [$this->configuration['theme']] : []), 
--- a/core/modules/system/src/Plugin/Condition/CurrentThemeCondition.php
+++ b/core/modules/system/src/Plugin/Condition/CurrentThemeCondition.php
   * {@inheritdoc}
   */
  public function submitConfigurationForm(array &$form, FormStateInterface $form_state) {
-    $this->configuration['theme'] = $form_state->getValue('theme');
+    $this->configuration['themes'] = $form_state->getValue('themes');
-    $this->configuration['themes'] = $form_state->getValue('themes');
+    $this->configuration['themes'] = $form_state->getValue('themes');
+    unset($this->configuration['theme'];