diff --git a/tests/Eccube/Tests/Service/PluginServiceTest.php b/tests/Eccube/Tests/Service/PluginServiceTest.php
index 410830d4dae..bc0d3ad287b 100644
--- a/tests/Eccube/Tests/Service/PluginServiceTest.php
+++ b/tests/Eccube/Tests/Service/PluginServiceTest.php
@@ -134,6 +134,9 @@ public function testInstallPluginMinimum()
         }
         // 同じプラグインの二重インストールが蹴られるか
 
+        // --if-not-exists オプションの検証
+        $this->assertTrue($this->service->install($tmpfile, true), '--if-not-exists オプションを指定した場合は例外が発生しない');
+
         // アンインストールできるか
         $this->assertTrue((bool) $plugin = $this->pluginRepository->findOneBy(['code' => $tmpname]));
         $this->assertEquals(Constant::DISABLED, $plugin->isEnabled());
@@ -286,7 +289,7 @@ public function testInstallPluginWithBrokenManagerAfterInstall()
 namespace Plugin\@@@@ ;
 
 use Eccube\Plugin\AbstractPluginManager;
-use Symfony\Component\DependencyInjection\ContainerInterface;
+use Psr\Container\ContainerInterface;
 
 class PluginManager extends AbstractPluginManager
 {
@@ -353,7 +356,7 @@ public function testInstallPluginWithManager()
 namespace Plugin\@@@@ ;
 
 use Eccube\Plugin\AbstractPluginManager;
-use Symfony\Component\DependencyInjection\ContainerInterface;
+use Psr\Container\ContainerInterface;
 
 class PluginManager extends AbstractPluginManager
 {
@@ -556,7 +559,7 @@ public function testCreateEntityAndTrait()
 namespace Plugin\@@@@ ;
 
 use Eccube\Plugin\AbstractPluginManager;
-use Symfony\Component\DependencyInjection\ContainerInterface;
+use Psr\Container\ContainerInterface;
 
 class PluginManager extends AbstractPluginManager
 {