diff --git a/core/modules/filter/src/Plugin/Filter/FilterHtml.php b/core/modules/filter/src/Plugin/Filter/FilterHtml.php
index 175bfc6..0242dc9 100644
--- a/core/modules/filter/src/Plugin/Filter/FilterHtml.php
+++ b/core/modules/filter/src/Plugin/Filter/FilterHtml.php
@@ -75,7 +75,7 @@ public function settingsForm(array $form, FormStateInterface $form_state) {
    * Value callback for the allowed_html field.
    */
   public function allowedHtmlValueCallback($element, $input, FormStateInterface $form_state) {
-    return $input === FALSE ? $element['#default_value'] : FilterHtmlAllowedMarkupSchema::generateString($input);
+    return $input === FALSE ? $element['#default_value'] : FilterHtmlAllowedMarkupSchema::generateSettings($input);
   }
 
   /**
diff --git a/core/modules/filter/tests/src/Kernel/Migrate/d6/MigrateFilterFormatTest.php b/core/modules/filter/tests/src/Kernel/Migrate/d6/MigrateFilterFormatTest.php
index 81faf3e..82dfb48 100644
--- a/core/modules/filter/tests/src/Kernel/Migrate/d6/MigrateFilterFormatTest.php
+++ b/core/modules/filter/tests/src/Kernel/Migrate/d6/MigrateFilterFormatTest.php
@@ -40,7 +40,27 @@ public function testFilterFormat() {
     $this->assertFalse(isset($filters['filter_html_image_secure']));
 
     // Check variables migrated into filter.
-    $this->assertSame('<a href hreflang> <em> <strong> <cite> <code> <ul type> <ol start type> <li> <dl> <dt> <dd>', $filters['filter_html']['settings']['allowed_html']);
+    $this->assertSame([
+      'a' => [
+        'href' => '*',
+        'hreflang' => '*',
+      ],
+      'em' => [],
+      'strong' => [],
+      'cite' => [],
+      'code' => [],
+      'ul' => [
+        'type' => '*',
+      ],
+      'ol' => [
+        'start' => '*',
+        'type' => '*',
+      ],
+      'li' => [],
+      'dl' => [],
+      'dt' => [],
+      'dd' => [],
+    ], $filters['filter_html']['settings']['allowed_html']);
     $this->assertSame(TRUE, $filters['filter_html']['settings']['filter_html_help']);
     $this->assertSame(FALSE, $filters['filter_html']['settings']['filter_html_nofollow']);
     $this->assertSame(72, $filters['filter_url']['settings']['filter_url_length']);
diff --git a/core/modules/filter/tests/src/Kernel/Migrate/d7/MigrateFilterFormatTest.php b/core/modules/filter/tests/src/Kernel/Migrate/d7/MigrateFilterFormatTest.php
index 0f54245..cd2d392 100644
--- a/core/modules/filter/tests/src/Kernel/Migrate/d7/MigrateFilterFormatTest.php
+++ b/core/modules/filter/tests/src/Kernel/Migrate/d7/MigrateFilterFormatTest.php
@@ -70,7 +70,28 @@ public function testFilterFormat() {
     $format = FilterFormat::load('filtered_html');
     $this->assertInstanceOf(FilterFormatInterface::class, $format);
     $config = $format->filters('filter_html')->getConfiguration();
-    $this->assertSame('<div> <span> <ul type> <li> <ol start type> <a href hreflang> <img src alt height width>', $config['settings']['allowed_html']);
+    $this->assertSame([
+      'div' => [],
+      'span' => [],
+      'ul' => [
+        'type' => '*',
+      ],
+      'li' => [],
+      'ol' => [
+        'start' => '*',
+        'type' => '*',
+      ],
+      'a' => [
+        'href' => '*',
+        'hreflang' => '*',
+      ],
+      'img' => [
+        'src' => '*',
+        'alt' => '*',
+        'height' => '*',
+        'width' => '*',
+      ],
+    ], $config['settings']['allowed_html']);
     $config = $format->filters('filter_url')->getConfiguration();
     $this->assertSame(128, $config['settings']['filter_url_length']);