diff --git a/core/modules/filter/src/Element/ProcessedText.php b/core/modules/filter/src/Element/ProcessedText.php
index e0045d1..de9d5cc 100644
--- a/core/modules/filter/src/Element/ProcessedText.php
+++ b/core/modules/filter/src/Element/ProcessedText.php
@@ -80,7 +80,7 @@ public static function preRenderText($element) {
     }
     /** @var \Drupal\filter\Entity\FilterFormat $format **/
     $format = FilterFormat::load($format_id);
-    // If the requested text format doesn't exist or it's disabled, the text
+    // If the requested text format doesn't exist or its disabled, the text
     // cannot be filtered.
     if (!$format || !$format->status()) {
       $message = !$format ? 'Missing text format: %format.' : 'Disabled text format: %format.';
diff --git a/core/modules/filter/src/Entity/FilterFormat.php b/core/modules/filter/src/Entity/FilterFormat.php
index db136c9..3f01d7a 100644
--- a/core/modules/filter/src/Entity/FilterFormat.php
+++ b/core/modules/filter/src/Entity/FilterFormat.php
@@ -180,9 +180,10 @@ public function toArray() {
    * {@inheritdoc}
    */
   public function disable() {
-    // The fallback text format cannot be disabled.
+    // The fallback text format cannot be disabled, as we always have to be able
+    // to run it, in case a different format is disabled.
     if ($this->isFallbackFormat()) {
-      throw new \LogicException(sprintf("The fallback text format '%s' cannot be disabled.", $this->id()));
+      throw new \LogicException("The fallback text format '{$this->id()}' cannot be disabled.");
     }
 
     parent::disable();
diff --git a/core/modules/filter/src/Tests/FilterAdminTest.php b/core/modules/filter/src/Tests/FilterAdminTest.php
index eff64ca..54a7237 100644
--- a/core/modules/filter/src/Tests/FilterAdminTest.php
+++ b/core/modules/filter/src/Tests/FilterAdminTest.php
@@ -391,25 +391,19 @@ function testFilterTipHtmlEscape() {
   }
 
   /**
-   * Tests whether a field having a disabled format is rendered.
+   * Tests whether a field using a disabled format is rendered.
    */
   public function testDisabledFormat() {
-    // We test the interface as anonymous user.
-    $this->drupalLogout();
-
     // Create a node type and add a standard body field.
     $node_type = NodeType::create(['type' => Unicode::strtolower($this->randomMachineName())]);
     $node_type->save();
     node_add_body_field($node_type, $this->randomString());
 
-    // Create a new format and add a filter that replaces the text with a static
-    // text every time.
-    /** @var \Drupal\filter\FilterFormatInterface $format */
+    // Create a text format with a filter that returns a static string.
     $format = FilterFormat::create([
       'name' => $this->randomString(),
       'format' => $format_id = Unicode::strtolower($this->randomMachineName()),
     ]);
-    $format->save();
     $format->setFilterConfig('filter_static_text', ['status' => TRUE]);
     $format->save();
 
@@ -418,20 +412,20 @@ public function testDisabledFormat() {
       'type' => $node_type->id(),
       'title' => $this->randomString(),
     ]);
-    $body_value = 'body text &<';
+    $body_value = $this->randomString();
     $node->body->value = $body_value;
     $node->body->format = $format_id;
     $node->save();
 
     // The format is used and we should see the static text instead of the body
     // value.
-    $this->drupalGet('node/' . $node->id());
+    $this->drupalGet($node->urlInfo());
     $this->assertText('filtered text');
 
     // Disable the format.
     $format->disable()->save();
 
-    $this->drupalGet('node/' . $node->id());
+    $this->drupalGet($node->urlInfo());
 
     // The format is not used anymore.
     $this->assertNoText('filtered text');
@@ -450,7 +444,7 @@ public function testDisabledFormat() {
     $format_id = $this->randomMachineName();
     $node->body->format = $format_id;
     $node->save();
-    $this->drupalGet('node/' . $node->id());
+    $this->drupalGet($node->urlInfo());
     // The text is not displayed unfiltered or escaped.
     $this->assertNoRaw($body_value);
     $this->assertNoEscaped($body_value);
diff --git a/core/modules/filter/tests/filter_test_plugin/src/Plugin/Filter/FilterTestStatic.php b/core/modules/filter/tests/filter_test_plugin/src/Plugin/Filter/FilterTestStatic.php
new file mode 100644
index 0000000..0119642
--- /dev/null
+++ b/core/modules/filter/tests/filter_test_plugin/src/Plugin/Filter/FilterTestStatic.php
@@ -0,0 +1,33 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\filter_test_plugin\Plugin\Filter\FilterTestStatic.
+ */
+
+namespace Drupal\filter_test_plugin\Plugin\Filter;
+
+use Drupal\filter\FilterProcessResult;
+use Drupal\filter\Plugin\FilterBase;
+
+/**
+ * Provides a filter that returns the same static text, regardless of what input
+ * text he receives.
+ *
+ * @Filter(
+ *   id = "filter_static_text",
+ *   title = @Translation("Static filter"),
+ *   type = Drupal\filter\Plugin\FilterInterface::TYPE_HTML_RESTRICTOR,
+ *   settings = {},
+ * )
+ */
+class FilterTestStatic extends FilterBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function process($text, $langcode) {
+    return new FilterProcessResult('filtered text');
+  }
+
+}