diff --git a/cbpi/__init__.py b/cbpi/__init__.py
index 8c3a589..4618101 100644
--- a/cbpi/__init__.py
+++ b/cbpi/__init__.py
@@ -1 +1 @@
-__version__ = "4.0.0.51"
+__version__ = "4.0.0.52"
diff --git a/cbpi/extension/mashstep/__init__.py b/cbpi/extension/mashstep/__init__.py
index 2fe8dfd..ee7c924 100644
--- a/cbpi/extension/mashstep/__init__.py
+++ b/cbpi/extension/mashstep/__init__.py
@@ -15,7 +15,6 @@ from typing import KeysView
 from cbpi.api.config import ConfigType
 from cbpi.api.base import CBPiBase
 import numpy as np
-#import scipy.optimize
 import warnings
 
 
diff --git a/setup.py b/setup.py
index 6dc39e9..d293b75 100644
--- a/setup.py
+++ b/setup.py
@@ -37,10 +37,9 @@ setup(name='cbpi',
           'asyncio-mqtt',
           'psutil==5.8.0',
           'numpy==1.20.3',
-          'scipy',
           'cbpi4ui',
           'importlib_metadata'] + (
-              ['RPi.GPIO'] if platform.uname()[1] == "raspberrypi" else [] ),
+              ['RPi.GPIO==0.7.1a4'] if platform.uname()[1] == "raspberrypi" else [] ),
 
         dependency_links=[
         'https://testpypi.python.org/pypi',