diff --git a/README.md b/README.md
index 161855e32..a26aae804 100644
--- a/README.md
+++ b/README.md
@@ -38,8 +38,8 @@ A documentation created with [phpDocumentor](https://www.phpdoc.org/) can be fou
 
 ### Requirements
 - PHP 7.4+
-  - `ext-json`, `ext-mbstring`
-  - optional: `ext-gd`, `ext-imagick`
+  - `ext-mbstring`
+  - optional: `ext-json`, `ext-gd`, `ext-imagick`
 
 ### Installation
 **requires [composer](https://getcomposer.org)**
diff --git a/composer.json b/composer.json
index 47fec6b75..e6661d95b 100644
--- a/composer.json
+++ b/composer.json
@@ -25,7 +25,6 @@
 	],
 	"require": {
 		"php": "^7.4",
-		"ext-json": "*",
 		"ext-mbstring": "*",
 		"chillerlan/php-settings-container": "^1.2"
 	},
diff --git a/src/Output/QRString.php b/src/Output/QRString.php
index 53751f1ca..3ed5153e1 100644
--- a/src/Output/QRString.php
+++ b/src/Output/QRString.php
@@ -10,6 +10,7 @@
  * @license      MIT
  *
  * @noinspection PhpUnusedParameterInspection
+ * @noinspection PhpComposerExtensionStubsInspection
  */
 
 namespace chillerlan\QRCode\Output;