diff -u b/core/lib/Drupal/Core/Config/ConfigInstaller.php b/core/lib/Drupal/Core/Config/ConfigInstaller.php
--- b/core/lib/Drupal/Core/Config/ConfigInstaller.php
+++ b/core/lib/Drupal/Core/Config/ConfigInstaller.php
@@ -226,15 +226,7 @@
   }
 
   /**
-   * Installs all default configuration in a particular collection.
-   *
-   * The function is useful if the site needs to respond to an event that has
-   * just created another collection and we need to check all the installed
-   * extensions for any matching configuration. For example, if a language has
-   * just been created.
-   *
-   * @param string $collection
-   *   The configuration collection.
+   * {@inheritdoc}
    */
   public function installCollectionDefaultConfig($collection) {
     $config_to_install = $this->getSourceStorage($collection)->listAll();
diff -u b/core/lib/Drupal/Core/Config/ConfigManager.php b/core/lib/Drupal/Core/Config/ConfigManager.php
--- b/core/lib/Drupal/Core/Config/ConfigManager.php
+++ b/core/lib/Drupal/Core/Config/ConfigManager.php
@@ -173,6 +173,13 @@
     foreach ($config_names as $config_name) {
       $this->configFactory->get($config_name)->delete();
     }
+
+    // Remove any matching configuration from collections.
+    foreach ($this->activeStorage->getAllCollectionNames() as $collection) {
+      $collection_storage = $this->activeStorage->createCollection($collection);
+      $collection_storage->deleteAll($name . '.');
+    }
+
     $schema_dir = drupal_get_path($type, $name) . '/' . InstallStorage::CONFIG_SCHEMA_DIRECTORY;
     if (is_dir($schema_dir)) {
       // Refresh the schema cache if uninstalling an extension that provides
diff -u b/core/modules/config/lib/Drupal/config/Tests/ConfigInstallTest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigInstallTest.php
--- b/core/modules/config/lib/Drupal/config/Tests/ConfigInstallTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigInstallTest.php
@@ -133,6 +133,13 @@
     $collection_storage = $active_storage->createCollection('entity');
     $data = $collection_storage->read('config_test.dynamic.dotted.default');
     $this->assertIdentical(array('label' => 'entity'), $data);
+
+    // Test that the config manager uninstalls configuration from collections
+    // as expected.
+    \Drupal::service('config.manager')->uninstall('module', 'config_collection_install_test');
+    $this->assertEqual(array('entity'), $active_storage->getAllCollectionNames());
+    \Drupal::service('config.manager')->uninstall('module', 'config_test');
+    $this->assertEqual(array(), $active_storage->getAllCollectionNames());
   }
 
   /**
only in patch2:
unchanged:
--- a/core/lib/Drupal/Core/Config/ConfigInstallerInterface.php
+++ b/core/lib/Drupal/Core/Config/ConfigInstallerInterface.php
@@ -38,6 +38,19 @@
   public function installDefaultConfig($type, $name);
 
   /**
+   * Installs all default configuration in the specified collection.
+   *
+   * The function is useful if the site needs to respond to an event that has
+   * just created another collection and we need to check all the installed
+   * extensions for any matching configuration. For example, if a language has
+   * just been created.
+   *
+   * @param string $collection
+   *   The configuration collection.
+   */
+  public function installCollectionDefaultConfig($collection);
+
+  /**
    * Sets the configuration storage that provides the default configuration.
    *
    * @param \Drupal\Core\Config\StorageInterface $storage