diff --git a/tests/FunctionalTest.php b/tests/FunctionalTest.php
index a37040e..73b473d 100644
--- a/tests/FunctionalTest.php
+++ b/tests/FunctionalTest.php
@@ -37,6 +37,33 @@ protected function tearDown(): void
         }
     }
 
+    public function testItDoesNotDisplayGifWhenDebugIsDisabled(): void
+    {
+        $client = static::createClient(['environment' => 'dev', 'debug' => false]);
+
+        $client->request('GET', '/error-404');
+        $response = $client->getResponse();
+
+        self::assertSame(404, $response->getStatusCode());
+        self::assertStringNotContainsString('data-gif', (string) $response->getContent());
+        self::assertFalse(static::getContainer()->has('gif_exception.listener.replace_image'));
+    }
+
+    public function testItFallsBackToOtherGifsForNonHttpExceptions(): void
+    {
+        $client = static::createClient(['environment' => 'dev', 'debug' => true]);
+
+        $client->request('GET', '/database-error');
+        $response = $client->getResponse();
+
+        self::assertSame(500, $response->getStatusCode());
+
+        $image = $this->getImage((string) $response->getContent());
+
+        self::assertTrue($image->hasAttribute('data-gif'), 'Image was not replaced.');
+        self::assertStringMatchesFormat('%s/gifexception/images/other/%s.gif', $image->getAttribute('src'));
+    }
+
     public function testItDoesNotDisplayGifOnExceptionPageIfTheBundleIsNotEnabled(): void
     {
         $client = static::createClient(['environment' => 'prod', 'debug' => true]);
diff --git a/tests/app/config/routing.php b/tests/app/config/routing.php
index c34bb89..9b66e5b 100644
--- a/tests/app/config/routing.php
+++ b/tests/app/config/routing.php
@@ -16,6 +16,9 @@
         ->requirements(['status' => '\d+'])
         ->defaults(['_controller' => 'Joli\GifExceptionBundle\Tests\app\src\TestController::errorAction'])
     ;
+    $routes->add('test_routing_database_error', '/database-error')
+        ->defaults(['_controller' => 'Joli\GifExceptionBundle\Tests\app\src\TestController::databaseErrorAction'])
+    ;
 
     try {
         $routes->import('@WebProfilerBundle/Resources/config/routing/wdt.xml')
diff --git a/tests/app/src/TestController.php b/tests/app/src/TestController.php
index 9c82b4d..b25135a 100644
--- a/tests/app/src/TestController.php
+++ b/tests/app/src/TestController.php
@@ -22,4 +22,12 @@ public function errorAction(Request $request): void
 
         throw new HttpException($statusCode, \sprintf('This is HTTP %s error page!', $statusCode));
     }
+
+    public function databaseErrorAction(): void
+    {
+        // Mimic a PDOException whose code is a SQLSTATE string, not an int
+        throw new class('Database is on fire!') extends \PDOException {
+            protected $code = 'HY000';
+        };
+    }
 }