diff --git a/platformio/__init__.py b/platformio/__init__.py
index 3531ec67..7b31d423 100644
--- a/platformio/__init__.py
+++ b/platformio/__init__.py
@@ -1,7 +1,7 @@
 # Copyright (C) Ivan Kravets <me@ikravets.com>
 # See LICENSE for details.
 
-VERSION = (2, 3, 1)
+VERSION = (2, 3, "2.dev0")
 __version__ = ".".join([str(s) for s in VERSION])
 
 __title__ = "platformio"
diff --git a/setup.py b/setup.py
index fcf664e2..668ada4a 100644
--- a/setup.py
+++ b/setup.py
@@ -20,7 +20,7 @@ setup(
     install_requires=[
         "bottle",
         "click>=3.2",
-        "lockfile",
+        "lockfile>=0.9.1",
         "pyserial",
         "requests>=2.4.0",
         "SCons"