diff --git a/requirements.txt b/requirements.txt
index 533475e..06cfa7e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
 Flask==1.0.2
 Flask-Login==0.4.1
 pyserial==3.4
-
+pymodbus==2.2.0