diff --git a/tests/src/Unit/ConfigPatchTest.php b/tests/src/Unit/ConfigPatchTest.php
index fb5a9cc245305b08800dc2799f4963fc47c731f5..48fa45f3161eddd7243ae6210e2bab0f16222bba 100644
--- a/tests/src/Unit/ConfigPatchTest.php
+++ b/tests/src/Unit/ConfigPatchTest.php
@@ -4,6 +4,7 @@
 
 namespace Drupal\Tests\config_split\Unit;
 
+use Prophecy\PhpUnit\ProphecyTrait;
 use Drupal\config_split\Config\ConfigPatch;
 use Drupal\config_split\Config\ConfigPatchMerge;
 use Drupal\config_split\Config\ConfigSorter;
@@ -21,6 +22,7 @@
  */
 class ConfigPatchTest extends TestCase {
 
+  use ProphecyTrait;
   /**
    * The patch merge service under test.
    *