diff --git a/core/modules/color/lib/Drupal/color/Tests/ColorTest.php b/core/modules/color/lib/Drupal/color/Tests/ColorTest.php
index 9ddd06a..1a02f25 100644
--- a/core/modules/color/lib/Drupal/color/Tests/ColorTest.php
+++ b/core/modules/color/lib/Drupal/color/Tests/ColorTest.php
@@ -48,6 +48,7 @@ function setUp() {
       ),
     );
     theme_enable(array_keys($this->themes));
+    drupal_flush_all_caches();
 
     // Array filled with valid and not valid color values
     $this->colorTests = array(
diff --git a/core/modules/system/lib/Drupal/system/Tests/System/ThemeTest.php b/core/modules/system/lib/Drupal/system/Tests/System/ThemeTest.php
index f636849..d9e2adb 100644
--- a/core/modules/system/lib/Drupal/system/Tests/System/ThemeTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/System/ThemeTest.php
@@ -231,6 +231,8 @@ function testSwitchDefaultTheme() {
     $this->clickLink(t('Set default'));
     $this->assertEqual(config('system.theme')->get('default'), 'bartik');
 
+    drupal_flush_all_caches();
+
     // Test the default theme on the secondary links (blocks admin page).
     $this->drupalGet('admin/structure/block');
     $this->assertText('Bartik(' . t('active tab') . ')', 'Default local task on blocks admin page is the default theme.');