diff -u b/simplenews.install b/simplenews.install
--- b/simplenews.install
+++ b/simplenews.install
@@ -145,10 +145,43 @@
-
 /**
- * Remove simplenews_issue field type.
+ * Update the column.
  */
 function simplenews_update_8001() {
-  $config = \Drupal::config('simplenews.settings');
-  $config->clear('field.value.simplenews_issue.subscribers');
-  $config->save();
-  // @todo Erase from database.
+  update_entity_field('node', 'simplenews_issue', function ($schema) {
+    unset($schema['node__simplenews_issue']['fields']['unsigned']);
+    unset($schema['node__simplenews_issue']['fields']['size']);
+    \Drupal::database()->schema()->changeField('node__simplenews_issue', 'simplenews_issue_subscribers', '', $schema['simplenews']['fields']);
+  });
+}
+
+/**
+ * Allows to update an entity field table.
+ *
+ * @param string $entity_type_id
+ *   The entity type.
+ * @param string $field_name
+ *   The field name.
+ * @param callable $callback
+ *   A callback function that will be called with the original schema and is
+ *   responsible for updating it and also executing any necessary schema
+ *   changes.
+ */
+function update_entity_field($entity_type_id, $field_name, callable $callback) {
+  // Get the current schema.
+  $key_value_store_schema = \Drupal::keyValue('entity.storage_schema.sql');
+  $schema = $key_value_store_schema->get($entity_type_id . '.field_schema_data.' . $field_name);
+
+  // Executable the callback to update the schema and manually apply changes.
+  $callback($schema);
+
+  // Update the last installed field definition and field schema.
+  /** @var \Drupal\Core\KeyValueStore\KeyValueStoreInterface $key_value_store */
+  \Drupal::entityManager()->clearCachedFieldDefinitions();
+  $key_value_store_definition = \Drupal::keyValue('entity.definitions.installed');
+  $storage_definitions = $key_value_store_definition->get($entity_type_id . '.field_storage_definitions');
+  $storage_definitions[$field_name] = $storage_definition = \Drupal::entityManager()
+    ->getFieldStorageDefinitions($entity_type_id)[$field_name];
+  $key_value_store_definition->set($entity_type_id . '.field_storage_definitions', $storage_definitions);
+  // Update the stored schema.
+  $key_value_store_schema->set($entity_type_id . '.field_schema_data.' . $field_name, $schema);
 }
+