diff --git a/requirements.txt b/requirements.txt
index 11cfbb8cb..4954a1c81 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,7 @@
 fastcrc
 lxml>=3.6.0
 setuptools>=42
+pyserial>=3.5
 wheel>=0.37.1
 
 # dev dependencies: