diff -u b/core/modules/ckeditor/tests/src/FunctionalJavascript/CKEditorIntegrationTest.php b/core/modules/ckeditor/tests/src/FunctionalJavascript/CKEditorIntegrationTest.php
--- b/core/modules/ckeditor/tests/src/FunctionalJavascript/CKEditorIntegrationTest.php
+++ b/core/modules/ckeditor/tests/src/FunctionalJavascript/CKEditorIntegrationTest.php
@@ -99,11 +99,23 @@
     // the viewport.
     $web_assert->assertNotVisibleInViewport('css', $ckeditor_id, 'topLeft', 'CKEditor-enabled body field is visible.');
 
+    $before_url = $session->getCurrentUrl();
+
     // Trigger a hash change with as target the hidden textarea.
     $session->executeScript("location.hash = '#edit-body-0-value';");
 
     // Check that the CKEditor-enabled body field is visible in the viewport.
     $web_assert->assertVisibleInViewport('css', $ckeditor_id, 'topLeft', 'CKEditor-enabled body field is not visible.');
+
+    // Use JavaScript to go back in the history instead of
+    // \Behat\Mink\Session::back() because that function doesn't work after a
+    // hash change.
+    $session->executeScript("history.back();");
+
+    $after_url = $session->getCurrentUrl();
+
+    // Check that going back in the history worked.
+    self::assertEquals($before_url, $after_url, 'History back works.');
   }
 
 }
diff -u b/core/modules/inline_form_errors/tests/src/FunctionalJavascript/FormErrorHandlerCKEditorTest.php b/core/modules/inline_form_errors/tests/src/FunctionalJavascript/FormErrorHandlerCKEditorTest.php
--- b/core/modules/inline_form_errors/tests/src/FunctionalJavascript/FormErrorHandlerCKEditorTest.php
+++ b/core/modules/inline_form_errors/tests/src/FunctionalJavascript/FormErrorHandlerCKEditorTest.php
@@ -77,6 +77,8 @@
    */
   public function testFragmentLink() {
     $session = $this->getSession();
+    $web_assert = $this->assertSession();
+    $ckeditor_id = '#cke_edit-body-0-value';
 
     $this->drupalGet('node/add/page');
 
@@ -91,27 +93,9 @@
     // visible. PhantomJS runs with a resolution of 1024x768px.
     $session->executeScript("document.getElementById('edit-title-0-value').style.marginBottom = '800px';");
 
-    // Javascript to test if top of the CKEditor-enabled body field is visible
-    // in the viewport. The NodeElement::isVisible() method doesn't take the
-    // viewport into account.
-    $visibility_check_javascript = <<<JS
-    (function(){
-        var w = window,
-        d = document,
-        e = d.documentElement,
-        el = d.getElementById('cke_edit-body-0-value'),
-        r = el.getBoundingClientRect();
-
-        return (
-          r.top >= 0 &&
-          r.top < (w.innerHeight || e.clientHeight)
-        );
-    }());
-JS;
-
     // Check that the CKEditor-enabled body field is currently not visible in
     // the viewport.
-    $this->assertFalse($session->evaluateScript($visibility_check_javascript), 'CKEditor-enabled body field is not visible.');
+    $web_assert->assertNotVisibleInViewport('css', $ckeditor_id, 'topLeft', 'CKEditor-enabled body field is not visible.');
 
     // Check if we can find the error fragment link within the errors summary
     // message.
@@ -121,7 +105,7 @@
     $errors_link->click();
 
     // Check that the CKEditor-enabled body field is visible in the viewport.
-    $this->assertTrue($session->evaluateScript($visibility_check_javascript), 'CKEditor-enabled body field is visible.');
+    $web_assert->assertVisibleInViewport('css', $ckeditor_id, 'topLeft', 'CKEditor-enabled body field is visible.');
   }
 
 }