diff --git a/core/modules/simpletest/tests/src/Functional/BrowserTestBaseTest.php b/core/modules/simpletest/tests/src/Functional/BrowserTestBaseTest.php
index 4448454..e1c08bb 100644
--- a/core/modules/simpletest/tests/src/Functional/BrowserTestBaseTest.php
+++ b/core/modules/simpletest/tests/src/Functional/BrowserTestBaseTest.php
@@ -68,7 +68,8 @@ public function testForm() {
     $this->assertSession()->hiddenFieldValueNotEquals('strawberry', 'brown');
     $this->assertSession()->hiddenFieldValueEquals('strawberry', 'red');
 
-    // Check that a hidden filed does not exist.
+    // Check that a hidden field does not exist.
+    $this->assertSession()->hiddenFieldNotExists('bananas');
     $this->assertSession()->hiddenFieldNotExists('pineapple');
 
     $edit = ['bananas' => 'green'];
diff --git a/core/tests/Drupal/Tests/WebAssert.php b/core/tests/Drupal/Tests/WebAssert.php
index b1fb35d..9eb9842 100644
--- a/core/tests/Drupal/Tests/WebAssert.php
+++ b/core/tests/Drupal/Tests/WebAssert.php
@@ -476,7 +476,7 @@ public function hiddenFieldValueEquals($field, $value, TraversableElement $conta
     $node = $this->hiddenFieldExists($field, $container);
     $actual = $node->getValue();
     $regex = '/^'.preg_quote($value, '/').'$/ui';
-    $message = sprintf('The hidden field "%s" value is "%s", but "%s" expected.', $field, $actual, $value);
+    $message = "The hidden field '$field' value is '$actual', but '$value' expected.";
     $this->assert((bool) preg_match($regex, $actual), $message);
   }
 
@@ -497,7 +497,7 @@ public function hiddenFieldValueNotEquals($field, $value, TraversableElement $co
     $node = $this->hiddenFieldExists($field, $container);
     $actual = $node->getValue();
     $regex = '/^'.preg_quote($value, '/').'$/ui';
-    $message = sprintf('The hidden field "%s" value is "%s", but it should not be.', $field, $actual);
+    $message = "The hidden field '$field' value is '$actual', but it should not be.";
     $this->assert(!preg_match($regex, $actual), $message);
   }