diff --git a/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationBrowser.php b/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationBrowser.php
index 8e8ce12..5b9a68d 100644
--- a/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationBrowser.php
+++ b/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationBrowser.php
@@ -7,8 +7,6 @@
 
 namespace Drupal\Core\Language\Plugin\LanguageNegotiation;
 
-use Drupal\Component\Annotation\Plugin;
-use Drupal\Core\Annotation\Translation;
 use Drupal\Core\Language\LanguageNegotiationMethodBase;
 use Symfony\Component\HttpFoundation\Request;
 
@@ -28,7 +26,7 @@
  * otherwise we would cache a user-specific preference.
  *
  * @Plugin(
- *   id = LanguageNegotiationBrowser::METHOD_ID,
+ *   id = Drupal\Core\Language\Plugin\LanguageNegotiation\LanguageNegotiationBrowser::METHOD_ID,
  *   weight = -2,
  *   cache = 0,
  *   name = @Translation("Browser"),
diff --git a/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationSelected.php b/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationSelected.php
index 8dce46d..4c48934 100644
--- a/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationSelected.php
+++ b/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationSelected.php
@@ -7,8 +7,6 @@
 
 namespace Drupal\Core\Language\Plugin\LanguageNegotiation;
 
-use Drupal\Component\Annotation\Plugin;
-use Drupal\Core\Annotation\Translation;
 use Drupal\Core\Language\LanguageNegotiationMethodBase;
 use Symfony\Component\HttpFoundation\Request;
 
@@ -16,7 +14,7 @@
  * Class for identifying language from a selected language.
  *
  * @Plugin(
- *   id = LanguageNegotiationSelected::METHOD_ID,
+ *   id = Drupal\Core\Language\Plugin\LanguageNegotiation\LanguageNegotiationSelected::METHOD_ID,
  *   weight = 12,
  *   name = @Translation("Selected language"),
  *   description = @Translation("Language based on a selected language."),
diff --git a/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationSession.php b/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationSession.php
index 07fbb6a..759d5d4 100644
--- a/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationSession.php
+++ b/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationSession.php
@@ -7,8 +7,6 @@
 
 namespace Drupal\Core\Language\Plugin\LanguageNegotiation;
 
-use Drupal\Component\Annotation\Plugin;
-use Drupal\Core\Annotation\Translation;
 use Drupal\Core\Language\LanguageNegotiationMethodBase;
 use Symfony\Component\HttpFoundation\Request;
 
@@ -16,7 +14,7 @@
  * Identify language from a request/session parameter.
  *
  * @Plugin(
- *   id = LanguageNegotiationSession::METHOD_ID,
+ *   id = Drupal\Core\Language\Plugin\LanguageNegotiation\LanguageNegotiationSession::METHOD_ID,
  *   weight = -6,
  *   name = @Translation("Session"),
  *   description = @Translation("Language from a request/session parameter."),
diff --git a/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUI.php b/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUI.php
index 7cba9bf..6492d6f 100644
--- a/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUI.php
+++ b/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUI.php
@@ -7,9 +7,6 @@
 
 namespace Drupal\Core\Language\Plugin\LanguageNegotiation;
 
-use Drupal\Component\Annotation\Plugin;
-use Drupal\Core\Annotation\Translation;
-use Drupal\Core\Language\Language;
 use Drupal\Core\Language\LanguageNegotiationMethodBase;
 use Symfony\Component\HttpFoundation\Request;
 
@@ -17,8 +14,8 @@
  * Class for identifying the language from the current interface language.
  *
  * @Plugin(
- *   id = LanguageNegotiationUI::METHOD_ID,
- *   types = {Language::TYPE_CONTENT},
+ *   id = Drupal\Core\Language\Plugin\LanguageNegotiation\LanguageNegotiationUI::METHOD_ID,
+ *   types = {Drupal\Core\Language\Language::TYPE_CONTENT},
  *   weight = 9,
  *   name = @Translation("Interface"),
  *   description = @Translation("Use the detected interface language.")
diff --git a/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUrl.php b/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUrl.php
index 02147bc..756d602 100644
--- a/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUrl.php
+++ b/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUrl.php
@@ -7,8 +7,6 @@
 
 namespace Drupal\Core\Language\Plugin\LanguageNegotiation;
 
-use Drupal\Component\Annotation\Plugin;
-use Drupal\Core\Annotation\Translation;
 use Drupal\Core\Language\LanguageNegotiationMethodBase;
 use Symfony\Component\HttpFoundation\Request;
 
@@ -16,7 +14,7 @@
  * Class for identifying language via URL prefix or domain.
  *
  * @Plugin(
- *   id = LanguageNegotiationUrl::METHOD_ID,
+ *   id = Drupal\Core\Language\Plugin\LanguageNegotiation\LanguageNegotiationUrl::METHOD_ID,
  *   weight = -8,
  *   name = @Translation("URL"),
  *   description = @Translation("Language from the URL (Path prefix or domain)."),
diff --git a/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUrlFallback.php b/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUrlFallback.php
index 637fa4e..bd47eaa 100644
--- a/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUrlFallback.php
+++ b/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUrlFallback.php
@@ -7,9 +7,6 @@
 
 namespace Drupal\Core\Language\Plugin\LanguageNegotiation;
 
-use Drupal\Component\Annotation\Plugin;
-use Drupal\Core\Annotation\Translation;
-use Drupal\Core\Language\Language;
 use Drupal\Core\Language\LanguageNegotiationMethodBase;
 use Symfony\Component\HttpFoundation\Request;
 
@@ -36,8 +33,8 @@
  *     page matching the detected interface language.
  *
  * @Plugin(
- *   id = LanguageNegotiationUrlFallback::METHOD_ID,
- *   types = {Language::TYPE_URL},
+ *   id = Drupal\Core\Language\Plugin\LanguageNegotiation\LanguageNegotiationUrlFallback::METHOD_ID,
+ *   types = {Drupal\Core\Language\Language::TYPE_URL},
  *   weight = 8,
  *   name = @Translation("URL fallback"),
  *   description = @Translation("Use an already detected language for URLs if none is found..")
diff --git a/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUser.php b/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUser.php
index 85d2da2..7084d94 100644
--- a/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUser.php
+++ b/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUser.php
@@ -7,8 +7,6 @@
 
 namespace Drupal\Core\Language\Plugin\LanguageNegotiation;
 
-use Drupal\Component\Annotation\Plugin;
-use Drupal\Core\Annotation\Translation;
 use Drupal\Core\Language\LanguageNegotiationMethodBase;
 use Symfony\Component\HttpFoundation\Request;
 
@@ -16,7 +14,7 @@
  * Class for identifying language from the user preferences.
  *
  * @Plugin(
- *   id = LanguageNegotiationUser::METHOD_ID,
+ *   id = {Drupal\Core\Language\Plugin\LanguageNegotiation\LanguageNegotiationUser::METHOD_ID},
  *   weight = -4,
  *   name = @Translation("User"),
  *   description = @Translation("Follow the user's language preference.")
diff --git a/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUserAdmin.php b/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUserAdmin.php
index 6a9ff9f..21ba800 100644
--- a/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUserAdmin.php
+++ b/core/lib/Drupal/Core/Language/Plugin/LanguageNegotiation/LanguageNegotiationUserAdmin.php
@@ -7,9 +7,6 @@
 
 namespace Drupal\Core\Language\Plugin\LanguageNegotiation;
 
-use Drupal\Component\Annotation\Plugin;
-use Drupal\Core\Annotation\Translation;
-use Drupal\Core\Language\Language;
 use Drupal\Core\Language\LanguageNegotiationMethodBase;
 use Symfony\Component\HttpFoundation\Request;
 
@@ -17,8 +14,8 @@
  * Identifies admin language from the user preferences.
  *
  * @Plugin(
- *   id = LanguageNegotiationUserAdmin::METHOD_ID,
- *   types = {Language::TYPE_INTERFACE},
+ *   id = Drupal\Core\Language\Plugin\LanguageNegotiation\LanguageNegotiationUserAdmin::METHOD_ID,
+ *   types = {Drupal\Core\Language\Language::TYPE_INTERFACE},
  *   weight = 10,
  *   name = @Translation("Account administration pages"),
  *   description = @Translation("Account administration pages language setting.")