diff --git a/src/compas_timber/ghpython/components/CT_Joint_Rule_Category/code.py b/src/compas_timber/ghpython/components/CT_Joint_Rule_Category/code.py
index 81ee31977..c6e58ce63 100644
--- a/src/compas_timber/ghpython/components/CT_Joint_Rule_Category/code.py
+++ b/src/compas_timber/ghpython/components/CT_Joint_Rule_Category/code.py
@@ -1,10 +1,9 @@
 from ghpythonlib.componentbase import executingcomponent as component
 from Grasshopper.Kernel.GH_RuntimeMessageLevel import Warning
-import clr
-import System
-import inspect
 from System.Windows.Forms import ToolStripSeparator
 from System.Windows.Forms import ToolStripMenuItem
+
+import inspect
 from collections import OrderedDict
 
 from compas_timber.connections import Joint
@@ -43,7 +42,7 @@ def RunScript(self, *args):
 
             kwargs = {}
             for i, val in enumerate(args[2:]):
-                if val != None:
+                if val is not None:
                     kwargs[self.arg_names()[i + 2]] = val
             print(kwargs)
             if not cat_a:
diff --git a/src/compas_timber/ghpython/components/CT_Joint_Rule_Direct/code.py b/src/compas_timber/ghpython/components/CT_Joint_Rule_Direct/code.py
index eec1438ac..30c8bcee2 100644
--- a/src/compas_timber/ghpython/components/CT_Joint_Rule_Direct/code.py
+++ b/src/compas_timber/ghpython/components/CT_Joint_Rule_Direct/code.py
@@ -37,7 +37,7 @@ def RunScript(self, *args):
             beam_b = args[1]
             kwargs = {}
             for i, val in enumerate(args[2:]):
-                if val != None:
+                if val is not None:
                     kwargs[self.arg_names()[i + 2]] = val
 
             if not beam_a:
diff --git a/src/compas_timber/ghpython/components/CT_Joint_Rule_Topology_L/code.py b/src/compas_timber/ghpython/components/CT_Joint_Rule_Topology_L/code.py
index 5f701497c..ef5dfe091 100644
--- a/src/compas_timber/ghpython/components/CT_Joint_Rule_Topology_L/code.py
+++ b/src/compas_timber/ghpython/components/CT_Joint_Rule_Topology_L/code.py
@@ -35,7 +35,7 @@ def RunScript(self, *args):
             ghenv.Component.Message = self.joint_type.__name__
             kwargs = {}
             for i, val in enumerate(args):
-                if val != None:
+                if val is not None:
                     kwargs[self.arg_names()[i]] = val
             if self.joint_type.SUPPORTED_TOPOLOGY != JointTopology.TOPO_L:
                 self.AddRuntimeMessage(Warning, "Joint type does not match topology. Joint may not be generated.")
diff --git a/src/compas_timber/ghpython/components/CT_Joint_Rule_Topology_T/code.py b/src/compas_timber/ghpython/components/CT_Joint_Rule_Topology_T/code.py
index 84f1c9827..97bd1c177 100644
--- a/src/compas_timber/ghpython/components/CT_Joint_Rule_Topology_T/code.py
+++ b/src/compas_timber/ghpython/components/CT_Joint_Rule_Topology_T/code.py
@@ -35,7 +35,7 @@ def RunScript(self, *args):
             ghenv.Component.Message = self.joint_type.__name__
             kwargs = {}
             for i, val in enumerate(args):
-                if val != None:
+                if val is not None:
                     kwargs[self.arg_names()[i]] = val
             if self.joint_type.SUPPORTED_TOPOLOGY != JointTopology.TOPO_T:
                 self.AddRuntimeMessage(Warning, "Joint type does not match topology. Joint may not be generated.")
diff --git a/src/compas_timber/ghpython/components/CT_Joint_Rule_Topology_X/code.py b/src/compas_timber/ghpython/components/CT_Joint_Rule_Topology_X/code.py
index 8271f5f2e..3ec154746 100644
--- a/src/compas_timber/ghpython/components/CT_Joint_Rule_Topology_X/code.py
+++ b/src/compas_timber/ghpython/components/CT_Joint_Rule_Topology_X/code.py
@@ -35,7 +35,7 @@ def RunScript(self, *args):
             ghenv.Component.Message = self.joint_type.__name__
             kwargs = {}
             for i, val in enumerate(args):
-                if val != None:
+                if val is not None:
                     kwargs[self.arg_names()[i]] = val
             if self.joint_type.SUPPORTED_TOPOLOGY != JointTopology.TOPO_X:
                 self.AddRuntimeMessage(Warning, "Joint type does not match topology. Joint may not be generated.")