diff --git a/platformio.ini b/platformio.ini
index 77938424f9..a3c990066a 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -200,7 +200,7 @@ build_unflags =
 ; This are common settings for the LibreTiny (all variants) using Arduino.
 [common:libretiny-arduino]
 extends = common:arduino
-platform = libretiny
+platform = libretiny@1.9.1
 framework = arduino
 lib_deps =
     droscy/esp_wireguard@0.4.2    ; wireguard