diff --git a/tests/src/Unit/DerivativeManagerCacheTest.php b/tests/src/Unit/DerivativeManagerCacheTest.php
index 414c1c1..ad4ac64 100644
--- a/tests/src/Unit/DerivativeManagerCacheTest.php
+++ b/tests/src/Unit/DerivativeManagerCacheTest.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\Tests\image_styles_builder\Unit;
 
+use Prophecy\PhpUnit\ProphecyTrait;
 use Drupal\Core\Cache\CacheBackendInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\image_styles_builder\DerivativeManager;
@@ -18,6 +19,7 @@ use Drupal\Tests\UnitTestCase;
  */
 final class DerivativeManagerCacheTest extends UnitTestCase {
 
+  use ProphecyTrait;
   /**
    * An instance of the DerivativeManager. This is the system under test.
    *
diff --git a/tests/src/Unit/ImageStyleFlusherTest.php b/tests/src/Unit/ImageStyleFlusherTest.php
index 1bae219..b07957a 100644
--- a/tests/src/Unit/ImageStyleFlusherTest.php
+++ b/tests/src/Unit/ImageStyleFlusherTest.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\Tests\image_styles_builder\Unit;
 
+use Prophecy\PhpUnit\ProphecyTrait;
 use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
 use Drupal\Core\Logger\LoggerChannelFactoryInterface;
@@ -20,6 +21,7 @@ use Psr\Log\LoggerInterface;
  */
 final class ImageStyleFlusherTest extends UnitTestCase {
 
+  use ProphecyTrait;
   /**
    * An instance of the ImageStyleFlusher.
    *
diff --git a/tests/src/Unit/ImageStyleGeneratorTest.php b/tests/src/Unit/ImageStyleGeneratorTest.php
index 1e1b3a3..73a2459 100644
--- a/tests/src/Unit/ImageStyleGeneratorTest.php
+++ b/tests/src/Unit/ImageStyleGeneratorTest.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\Tests\image_styles_builder\Unit;
 
+use Prophecy\PhpUnit\ProphecyTrait;
 use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
 use Drupal\Core\Logger\LoggerChannelFactoryInterface;
@@ -21,6 +22,7 @@ use Psr\Log\LoggerInterface;
  */
 final class ImageStyleGeneratorTest extends UnitTestCase {
 
+  use ProphecyTrait;
   /**
    * An instance of the ImageStyleGenerator.
    *