diff --git a/composer.json b/composer.json
index 9ec06fb8..bde774e6 100644
--- a/composer.json
+++ b/composer.json
@@ -26,7 +26,8 @@
 		"phpstan/phpstan": "^0.12"
 	},
 	"conflict": {
-		"nette/di": "<3.0.3"
+		"nette/di": "<3.0.3",
+		"nette/schema": "<1.1"
 	},
 	"suggest": {
 		"ext-fileinfo": "to detect type of uploaded files",
diff --git a/src/Bridges/HttpDI/HttpExtension.php b/src/Bridges/HttpDI/HttpExtension.php
index b43982c4..f5ca59ed 100644
--- a/src/Bridges/HttpDI/HttpExtension.php
+++ b/src/Bridges/HttpDI/HttpExtension.php
@@ -35,7 +35,7 @@ public function getConfigSchema(): Nette\Schema\Schema
 			'headers' => Expect::arrayOf('scalar|null')->default([
 				'X-Powered-By' => 'Nette Framework 3',
 				'Content-Type' => 'text/html; charset=utf-8',
-			]),
+			])->mergeDefaults(),
 			'frames' => Expect::anyOf(Expect::string(), Expect::bool(), null)->default('SAMEORIGIN'), // X-Frame-Options
 			'csp' => Expect::arrayOf('array|scalar|null'), // Content-Security-Policy
 			'cspReportOnly' => Expect::arrayOf('array|scalar|null'), // Content-Security-Policy-Report-Only