diff --git a/pio-scripts/auto_firmware_version.py b/pio-scripts/auto_firmware_version.py
index f169f617..26e1bd65 100644
--- a/pio-scripts/auto_firmware_version.py
+++ b/pio-scripts/auto_firmware_version.py
@@ -3,33 +3,27 @@
 # Copyright (C) 2022 Thomas Basler and others
 #
 import os
-import pkg_resources
 
 Import("env")
 
-required_pkgs = {'dulwich'}
-installed_pkgs = {pkg.key for pkg in pkg_resources.working_set}
-missing_pkgs = required_pkgs - installed_pkgs
-
-if missing_pkgs:
+try:
+    from dulwich import porcelain
+except ModuleNotFoundError:
     env.Execute('"$PYTHONEXE" -m pip install dulwich')
-
-from dulwich import porcelain
+    from dulwich import porcelain
 
 
 def updateFileIfChanged(filename, content):
     mustUpdate = True
     try:
-        fp = open(filename, "rb")
-        if fp.read() == content:
-            mustUpdate = False
-        fp.close()
+        with open(filename, "rb") as fp:
+            if fp.read() == content:
+                mustUpdate = False
     except:
         pass
     if mustUpdate:
-        fp = open(filename, "wb")
-        fp.write(content)
-        fp.close()
+        with open(filename, "wb") as fp:
+            fp.write(content)
     return mustUpdate