diff --git a/Dockerfile b/Dockerfile
index 93ad18a..b374d0c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -11,7 +11,7 @@ ARG CONF_DIR="${APP_DIR}/config"
 RUN \
     apt update && \
     pip3 install loguru && \
-    pip3 install pymodbus && \
+    pip3 install pymodbus==3.6.3 && \
     pip3 install paho-mqtt
 
 RUN \