diff --git a/tests/src/Functional/AddChildTest.php b/tests/src/Functional/AddChildTest.php
index f27f9db9..ed5282c7 100644
--- a/tests/src/Functional/AddChildTest.php
+++ b/tests/src/Functional/AddChildTest.php
@@ -9,13 +9,19 @@ namespace Drupal\Tests\islandora\Functional;
  */
 class AddChildTest extends IslandoraFunctionalTestBase {
 
+  /**
+   * The taxonomy term representing "Collection" items.
+   *
+   * @var \Drupal\taxonomy\TermInterface
+   */
+  protected $collectionTerm;
+
   /**
    * {@inheritdoc}
    */
   public function setUp(): void {
     parent::setUp();
 
-    $this->parent =
     $this->collectionTerm = $this->container->get('entity_type.manager')->getStorage('taxonomy_term')->create([
       'name' => 'Collection',
       'vid' => $this->testVocabulary->id(),
diff --git a/tests/src/Functional/JsonldSelfReferenceReactionTest.php b/tests/src/Functional/JsonldSelfReferenceReactionTest.php
index 92eca07a..1b4e24ec 100644
--- a/tests/src/Functional/JsonldSelfReferenceReactionTest.php
+++ b/tests/src/Functional/JsonldSelfReferenceReactionTest.php
@@ -12,6 +12,13 @@ use function GuzzleHttp\json_decode;
  */
 class JsonldSelfReferenceReactionTest extends IslandoraFunctionalTestBase {
 
+  /**
+   * An RDF Mapping object.
+   *
+   * @var \Drupal\rdf\Entity\RdfMapping
+   */
+  protected $rdfMapping;
+
   /**
    * {@inheritdoc}
    */
diff --git a/tests/src/Kernel/FedoraAdapterTest.php b/tests/src/Kernel/FedoraAdapterTest.php
index 9067d369..6d8fee28 100644
--- a/tests/src/Kernel/FedoraAdapterTest.php
+++ b/tests/src/Kernel/FedoraAdapterTest.php
@@ -354,7 +354,7 @@ class FedoraAdapterTest extends IslandoraKernelTestBase {
 
     $metadata = $adapter->read('');
     $this->assertFileMetadata($metadata);
-    $this->assertTrue($metadata['contents'] == "DERP", "Expecting 'content' of 'DERP', received '${metadata['contents']}'");
+    $this->assertTrue($metadata['contents'] == "DERP", "Expecting 'content' of 'DERP', received '{$metadata['contents']}'");
   }
 
   /**