diff --git a/tests/src/Functional/AddMediaToNodeTest.php b/tests/src/Functional/AddMediaToNodeTest.php
index 5e53a761..32909775 100644
--- a/tests/src/Functional/AddMediaToNodeTest.php
+++ b/tests/src/Functional/AddMediaToNodeTest.php
@@ -94,7 +94,7 @@ class AddMediaToNodeTest extends IslandoraFunctionalTestBase {
       'access content',
     ]);
     $this->drupalLogin($account);
-    $options['auth'] = [$account->getUsername(), $account->pass_raw];
+    $options['auth'] = [$account->getDisplayName(), $account->pass_raw];
     $response = $client->request('PUT', $add_to_node_url, $options);
     $this->assertTrue($response->getStatusCode() == 403, "Expected 403, received {$response->getStatusCode()}");
 
@@ -108,7 +108,7 @@ class AddMediaToNodeTest extends IslandoraFunctionalTestBase {
       'bypass node access',
     ]);
     $this->drupalLogin($account);
-    $options['auth'] = [$account->getUsername(), $account->pass_raw];
+    $options['auth'] = [$account->getDisplayName(), $account->pass_raw];
     $response = $client->request('PUT', $add_to_node_url, $options);
     $this->assertTrue($response->getStatusCode() == 403, "Expected 403, received {$response->getStatusCode()}");
 
@@ -121,7 +121,7 @@ class AddMediaToNodeTest extends IslandoraFunctionalTestBase {
 
     // Request without Content-Type header should fail with 400.
     $options = [
-      'auth' => [$account->getUsername(), $account->pass_raw],
+      'auth' => [$account->getDisplayName(), $account->pass_raw],
       'http_errors' => FALSE,
       'headers' => [
         'Content-Location' => 'public://test_file.txt',
@@ -133,7 +133,7 @@ class AddMediaToNodeTest extends IslandoraFunctionalTestBase {
 
     // Request without Content-Location header should fail with 400.
     $options = [
-      'auth' => [$account->getUsername(), $account->pass_raw],
+      'auth' => [$account->getDisplayName(), $account->pass_raw],
       'http_errors' => FALSE,
       'headers' => [
         'Content-Type' => 'text/plain',
@@ -145,7 +145,7 @@ class AddMediaToNodeTest extends IslandoraFunctionalTestBase {
 
     // Request without body should fail with 400.
     $options = [
-      'auth' => [$account->getUsername(), $account->pass_raw],
+      'auth' => [$account->getDisplayName(), $account->pass_raw],
       'http_errors' => FALSE,
       'headers' => [
         'Content-Type' => 'text/plain',
@@ -157,7 +157,7 @@ class AddMediaToNodeTest extends IslandoraFunctionalTestBase {
 
     // Test properly formed requests with bad parameters in the route.
     $options = [
-      'auth' => [$account->getUsername(), $account->pass_raw],
+      'auth' => [$account->getDisplayName(), $account->pass_raw],
       'http_errors' => FALSE,
       'headers' => [
         'Content-Type' => 'text/plain',
@@ -200,7 +200,7 @@ class AddMediaToNodeTest extends IslandoraFunctionalTestBase {
 
     // Should be successful with proper url, options, and permissions.
     $options = [
-      'auth' => [$account->getUsername(), $account->pass_raw],
+      'auth' => [$account->getDisplayName(), $account->pass_raw],
       'http_errors' => FALSE,
       'headers' => [
         'Content-Type' => 'text/plain',
diff --git a/tests/src/Functional/IslandoraFunctionalTestBase.php b/tests/src/Functional/IslandoraFunctionalTestBase.php
index 45326bc8..fcf77765 100644
--- a/tests/src/Functional/IslandoraFunctionalTestBase.php
+++ b/tests/src/Functional/IslandoraFunctionalTestBase.php
@@ -32,6 +32,8 @@ class IslandoraFunctionalTestBase extends BrowserTestBase {
     'menu_link_content',
   ];
 
+  protected $defaultTheme = 'stark';
+
   /**
    * {@inheritdoc}
    */
diff --git a/tests/src/FunctionalJavascript/IntegerWeightTest.php b/tests/src/FunctionalJavascript/IntegerWeightTest.php
index 5197f864..d74ea0ef 100644
--- a/tests/src/FunctionalJavascript/IntegerWeightTest.php
+++ b/tests/src/FunctionalJavascript/IntegerWeightTest.php
@@ -32,7 +32,7 @@ class IntegerWeightTest extends WebDriverTestBase {
     'integer_weight_test_views',
   ];
 
-  protected $defaultTheme = 'stable';
+  protected $defaultTheme = 'stark';
 
   /**
    * Name of the field.