diff --git a/core/modules/config/tests/src/Functional/ConfigImportBaseInstallProfileTest.php b/core/modules/config/tests/src/Functional/ConfigImportBaseInstallProfileTest.php
index 583c3115..d1fb659c 100644
--- a/core/modules/config/tests/src/Functional/ConfigImportBaseInstallProfileTest.php
+++ b/core/modules/config/tests/src/Functional/ConfigImportBaseInstallProfileTest.php
@@ -25,7 +25,7 @@ class ConfigImportBaseInstallProfileTest extends BrowserTestBase {
    */
   protected $webUser;
 
-  protected function setUp() {
+  protected function setUp(): void {
     parent::setUp();
 
     $this->webUser = $this->drupalCreateUser(['synchronize configuration']);
@@ -48,17 +48,19 @@ public function testInstallParentProfileValidation() {
     unset($core['module']['testing']);
     $sync->write('core.extension', $core);
 
-    $this->drupalPostForm('admin/config/development/configuration', [], t('Import all'));
-    $this->assertText('The configuration cannot be imported because it failed validation for the following reasons:');
-    $this->assertText('Unable to uninstall the Testing profile since it is a parent of another installed profile.');
+    $this->drupalGet('admin/config/development/configuration');
+    $this->submitForm([], 'Import all');
+    $this->assertSession()->pageTextContains('The configuration cannot be imported because it failed validation for the following reasons:');
+    $this->assertSession()->pageTextContains('Unable to uninstall the Testing profile since it is a parent of another installed profile.');
 
     // Uninstall dependencies of parent profile.
     $core['module']['testing'] = 0;
     unset($core['module']['dynamic_page_cache']);
     $sync->write('core.extension', $core);
     $sync->deleteAll('dynamic_page_cache.');
-    $this->drupalPostForm('admin/config/development/configuration', [], t('Import all'));
-    $this->assertText('The configuration was imported successfully.');
+    $this->drupalGet('admin/config/development/configuration');
+    $this->submitForm([], 'Import all');
+    $this->assertSession()->pageTextContains('The configuration was imported successfully.');
     $this->rebuildContainer();
     $this->assertFalse(\Drupal::moduleHandler()->moduleExists('dynamic_page_cache'), 'The dynamic_page_cache module has been uninstalled.');
   }
@@ -78,17 +80,19 @@ public function testInstallSubProfileValidation() {
     unset($core['module']['testing_inherited']);
     $sync->write('core.extension', $core);
 
-    $this->drupalPostForm('admin/config/development/configuration', [], t('Import all'));
-    $this->assertText('The configuration cannot be imported because it failed validation for the following reasons:');
-    $this->assertText('Unable to uninstall the Testing Inherited profile since it is the main install profile.');
+    $this->drupalGet('admin/config/development/configuration');
+    $this->submitForm([], 'Import all');
+    $this->assertSession()->pageTextContains('The configuration cannot be imported because it failed validation for the following reasons:');
+    $this->assertSession()->pageTextContains('Unable to uninstall the Testing Inherited profile since it is the main install profile.');
 
     // Uninstall dependencies of main profile.
     $core['module']['testing_inherited'] = 0;
     unset($core['module']['syslog']);
     $sync->write('core.extension', $core);
     $sync->deleteAll('syslog.');
-    $this->drupalPostForm('admin/config/development/configuration', [], t('Import all'));
-    $this->assertText('The configuration was imported successfully.');
+    $this->drupalGet('admin/config/development/configuration');
+    $this->submitForm([], 'Import all');
+    $this->assertSession()->pageTextContains('The configuration was imported successfully.');
     $this->rebuildContainer();
     $this->assertFalse(\Drupal::moduleHandler()->moduleExists('syslog'), 'The syslog module has been uninstalled.');
   }
diff --git a/core/tests/Drupal/KernelTests/Core/Extension/ProfileExtensionListTest.php b/core/tests/Drupal/KernelTests/Core/Extension/ProfileExtensionListTest.php
index 0c8faa21..1d767453 100644
--- a/core/tests/Drupal/KernelTests/Core/Extension/ProfileExtensionListTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Extension/ProfileExtensionListTest.php
@@ -85,7 +85,7 @@ public function testGetAncestors() {
    */
   public function testSelectDistribution() {
     $profile_list = new TestProfileExtensionList(
-      $this->container->get('app.root'),
+      $this->container->getParameter('app.root'),
       'profile',
       $this->container->get('cache.default'),
       $this->container->get('info_parser'),