diff -u b/core/modules/migrate/tests/src/Kernel/MigrateRollbackTest.php b/core/modules/migrate/tests/src/Kernel/MigrateRollbackTest.php
--- b/core/modules/migrate/tests/src/Kernel/MigrateRollbackTest.php
+++ b/core/modules/migrate/tests/src/Kernel/MigrateRollbackTest.php
@@ -4,6 +4,7 @@
 
 use Drupal\migrate\MigrateExecutable;
 use Drupal\migrate\Plugin\MigrateIdMapInterface;
+use Drupal\migrate\Plugin\migrate\id_map\Sql;
 use Drupal\migrate\Row;
 use Drupal\taxonomy\Entity\Term;
 use Drupal\taxonomy\Entity\Vocabulary;
diff -u b/core/modules/migrate_drupal_ui/src/Tests/MigrateUpgradeTestBase.php b/core/modules/migrate_drupal_ui/src/Tests/MigrateUpgradeTestBase.php
--- b/core/modules/migrate_drupal_ui/src/Tests/MigrateUpgradeTestBase.php
+++ b/core/modules/migrate_drupal_ui/src/Tests/MigrateUpgradeTestBase.php
@@ -158,6 +158,7 @@
       $source_id_field = [];
       foreach ($migration->getSourcePlugin()->getIds() as $field => $schema) {
         $source_id_field['sourceid' . $count] = $field;
+        $count++;
       }
       $id_map = $migration->getIdMap();
       foreach ($id_map as $source_id => $map) {