diff --git a/platformio.ini b/platformio.ini
index 4ce1db60..73b25822 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -23,7 +23,7 @@ build_flags =
 
 lib_deps =
     https://github.com/yubox-node-org/ESPAsyncWebServer
-    bblanchon/ArduinoJson @ ^6.20.1
+    bblanchon/ArduinoJson @ ^6.21.0
     https://github.com/bertmelis/espMqttClient.git#v1.4.1
     nrf24/RF24 @ ^1.4.5
     olikraus/U8g2 @ ^2.34.13