diff --git a/platformio.ini b/platformio.ini
index 0d919308..b695c247 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -68,7 +68,7 @@ build_flags =
 ; Warning : don't put comments after github links => causes infinite download loop
 lib_deps =
     bxparks/AceButton@^1.8.3         ; GPIO button library
-    bblanchon/ArduinoJson@^6.18.0    ; Json(l) parser
+    bblanchon/ArduinoJson@^6.17.3    ; Json(l) parser
     bblanchon/StreamUtils@1.6.0      ; for EEPromStream
     knolleary/PubSubClient@^2.8.0    ; MQTT client
     git+https://github.com/fvanroie/ConsoleInput.git