diff -u b/core/modules/user/tests/src/Kernel/UserDataQueryTest.php b/core/modules/user/tests/src/Kernel/UserDataQueryTest.php
--- b/core/modules/user/tests/src/Kernel/UserDataQueryTest.php
+++ b/core/modules/user/tests/src/Kernel/UserDataQueryTest.php
@@ -58,29 +58,37 @@
     $name = $this->randomMachineName();
     $module = $this->randomMachineName();
     $value = mt_rand(20, 30);
-    $result = [
+    $scalar_result = [
       'module' => $module,
       'uid' => $uid,
       'name' => $name,
-      'value' => $value
+      'value' => $value,
     ];
-    $row = [
-      $result,
-      [
-        'module' => $module . '_',
-        'uid' => $uid + 1,
-        'name' => $name . '_',
-        'value' => $value + 1,
-      ],
+    $array_result = [
+      'module' => $module . '_',
+      'uid' => $uid + 1,
+      'name' => $name . '_',
+      'value' => [$value],
+    ];
+    $contents = [
+      $scalar_result,
+      $array_result,
     ];
     return [
-      [$row, $module, $uid, $name, NULL, $result],
-      [$row, $module, $uid, NULL, $value, $result],
-      [$row, $module, NULL, $name, $value, $result],
-      [$row, $module, $uid, NULL, NULL, $result],
-      [$row, $module, NULL, $name, NULL, $result],
-      [$row, $module, NULL, NULL, $value, $result],
-      [$row, $module, NULL, NULL, NULL, $result],
+      [$contents, $module, $uid, $name, NULL, $scalar_result],
+      [$contents, $module, $uid, NULL, $value, $scalar_result],
+      [$contents, $module, NULL, $name, $value, $scalar_result],
+      [$contents, $module, $uid, NULL, NULL, $scalar_result],
+      [$contents, $module, NULL, $name, NULL, $scalar_result],
+      [$contents, $module, NULL, NULL, $value, $scalar_result],
+      [$contents, $module, NULL, NULL, NULL, $scalar_result],
+      [$contents, $module . '_', $uid + 1, $name . '_', NULL, $array_result],
+      [$contents, $module . '_', $uid + 1, NULL, [$value], $array_result],
+      [$contents, $module . '_', NULL, $name . '_', [$value], $array_result],
+      [$contents, $module . '_', $uid + 1, NULL, NULL, $array_result],
+      [$contents, $module . '_', NULL, $name . '_', NULL, $array_result],
+      [$contents, $module . '_', NULL, NULL, [$value], $array_result],
+      [$contents, $module . '_', NULL, NULL, NULL, $array_result],
     ];
   }