diff -u b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationProvidersExistTest.php b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationProvidersExistTest.php
--- b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationProvidersExistTest.php
+++ b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationProvidersExistTest.php
@@ -161,8 +161,8 @@
     $plugin_manager = $this->container->get('plugin.manager.migrate.field');
     $definitions = $plugin_manager->getDefinitions();
     foreach ($definitions as $key => $definition) {
-      $this->assertEquals($expected_mappings[$key]['source_module'], $plugin_manager->getSourceModule($definition));
-      $this->assertEquals($expected_mappings[$key]['destination_module'], $plugin_manager->getDestinationModule($definition));
+      $this->assertEquals($expected_mappings[$key]['source_module'], $definition['source_module']);
+      $this->assertEquals($expected_mappings[$key]['destination_module'], $definition['destination_module']);
     }
   }