diff --git a/src/Symfony/Tests/Bundle/DependencyInjection/ApiPlatformExtensionTest.php b/src/Symfony/Tests/Bundle/DependencyInjection/ApiPlatformExtensionTest.php
index 29e184fd13..2110e1814f 100644
--- a/src/Symfony/Tests/Bundle/DependencyInjection/ApiPlatformExtensionTest.php
+++ b/src/Symfony/Tests/Bundle/DependencyInjection/ApiPlatformExtensionTest.php
@@ -381,4 +381,15 @@ public function testPaginationMaximumItemsPerPageIsSetWithZero(): void
 
         $this->assertSame(0, $this->container->getParameter('api_platform.collection.pagination.maximum_items_per_page'));
     }
+
+    public function testPaginationMaximumItemsPerPageWhenDefaultsKeyIsMissing(): void
+    {
+        $config = self::DEFAULT_CONFIG;
+        $apiPlatformConfig = $config['api_platform'];
+        unset($apiPlatformConfig['defaults']);
+        (new ApiPlatformExtension())->load($config, $this->container);
+
+        $this->assertTrue($this->container->hasParameter('api_platform.collection.pagination.maximum_items_per_page'));
+        $this->assertSame(30, $this->container->getParameter('api_platform.collection.pagination.maximum_items_per_page'));
+    }
 }