diff --git a/Pymodbus/Pipfile b/Pymodbus/Pipfile
index 817f893..3f371c0 100644
--- a/Pymodbus/Pipfile
+++ b/Pymodbus/Pipfile
@@ -15,5 +15,5 @@ ipython = "*"
 [dev-packages]
 
 [requires]
-python_version = "3.10.6"
+python_version = "3.9"