diff --git a/py27/bacpypes/apdu.py b/py27/bacpypes/apdu.py
index 3421456..a258440 100755
--- a/py27/bacpypes/apdu.py
+++ b/py27/bacpypes/apdu.py
@@ -12,7 +12,7 @@ from .primitivedata import *
 from .constructeddata import *
 from .basetypes import *
 
-# some debuging
+# some debugging
 _debug = 0
 _log = ModuleLogger(globals())
 
diff --git a/py27/bacpypes/appservice.py b/py27/bacpypes/appservice.py
index cfa2a27..f2a48f6 100755
--- a/py27/bacpypes/appservice.py
+++ b/py27/bacpypes/appservice.py
@@ -14,7 +14,7 @@ from .task import OneShotTask
 
 from .apdu import *
 
-# some debuging
+# some debugging
 _debug = 0
 _log = ModuleLogger(globals())
 
@@ -653,6 +653,7 @@ class ClientSSM(SSM):
 #   ServerSSM - Server Segmentation State Machine
 #
 
+@bacpypes_debugging
 class ServerSSM(SSM):
 
     def __init__(self, sap):
@@ -1233,6 +1234,7 @@ class StateMachineAccessPoint(DeviceInfo, Client, ServiceAccessPoint):
 #   ApplicationServiceAccessPoint
 #
 
+@bacpypes_debugging
 class ApplicationServiceAccessPoint(ApplicationServiceElement, ServiceAccessPoint):
 
     def __init__(self, aseID=None, sapID=None):
diff --git a/py27/bacpypes/basetypes.py b/py27/bacpypes/basetypes.py
index 339ffbf..a2cc055 100755
--- a/py27/bacpypes/basetypes.py
+++ b/py27/bacpypes/basetypes.py
@@ -10,7 +10,7 @@ from .debugging import ModuleLogger
 from .primitivedata import *
 from .constructeddata import *
 
-# some debuging
+# some debugging
 _debug = 0
 _log = ModuleLogger(globals())
 
diff --git a/py27/bacpypes/bsll.py b/py27/bacpypes/bsll.py
index a874c69..d81cd27 100755
--- a/py27/bacpypes/bsll.py
+++ b/py27/bacpypes/bsll.py
@@ -11,7 +11,7 @@ from .debugging import ModuleLogger, DebugContents, bacpypes_debugging
 
 from .pdu import *
 
-# some debuging
+# some debugging
 _debug = 0
 _log = ModuleLogger(globals())
 
diff --git a/py27/bacpypes/bsllservice.py b/py27/bacpypes/bsllservice.py
index c663b6c..f574dad 100755
--- a/py27/bacpypes/bsllservice.py
+++ b/py27/bacpypes/bsllservice.py
@@ -17,7 +17,7 @@ from .netservice import NetworkAdapter
 
 from .bsll import *
 
-# some debuging
+# some debugging
 _debug = 0
 _log = ModuleLogger(globals())
 
diff --git a/py27/bacpypes/bvll.py b/py27/bacpypes/bvll.py
index 5edd202..af79478 100755
--- a/py27/bacpypes/bvll.py
+++ b/py27/bacpypes/bvll.py
@@ -9,7 +9,7 @@ from .debugging import ModuleLogger, DebugContents, bacpypes_debugging
 
 from .pdu import *
 
-# some debuging
+# some debugging
 _debug = 0
 _log = ModuleLogger(globals())
 
diff --git a/py27/bacpypes/bvllservice.py b/py27/bacpypes/bvllservice.py
index 73bdc57..7134016 100755
--- a/py27/bacpypes/bvllservice.py
+++ b/py27/bacpypes/bvllservice.py
@@ -19,7 +19,7 @@ from .comm import Client, Server, bind, \
 
 from .bvll import *
 
-# some debuging
+# some debugging
 _debug = 0
 _log = ModuleLogger(globals())
 
diff --git a/py34/bacpypes/apdu.py b/py34/bacpypes/apdu.py
index 3421456..a258440 100755
--- a/py34/bacpypes/apdu.py
+++ b/py34/bacpypes/apdu.py
@@ -12,7 +12,7 @@ from .primitivedata import *
 from .constructeddata import *
 from .basetypes import *
 
-# some debuging
+# some debugging
 _debug = 0
 _log = ModuleLogger(globals())
 
diff --git a/py34/bacpypes/appservice.py b/py34/bacpypes/appservice.py
index cfa2a27..83811db 100755
--- a/py34/bacpypes/appservice.py
+++ b/py34/bacpypes/appservice.py
@@ -14,7 +14,7 @@ from .task import OneShotTask
 
 from .apdu import *
 
-# some debuging
+# some debugging
 _debug = 0
 _log = ModuleLogger(globals())
 
@@ -653,6 +653,7 @@ class ClientSSM(SSM):
 #   ServerSSM - Server Segmentation State Machine
 #
 
+@bacpypes_debugging
 class ServerSSM(SSM):
 
     def __init__(self, sap):
@@ -1233,6 +1234,7 @@ class StateMachineAccessPoint(DeviceInfo, Client, ServiceAccessPoint):
 #   ApplicationServiceAccessPoint
 #
 
+@bacpypes_debugging
 class ApplicationServiceAccessPoint(ApplicationServiceElement, ServiceAccessPoint):
 
     def __init__(self, aseID=None, sapID=None):
@@ -1382,4 +1384,3 @@ class ApplicationServiceAccessPoint(ApplicationServiceElement, ServiceAccessPoin
 
         # forward the encoded packet
         self.response(xpdu)
-
diff --git a/py34/bacpypes/basetypes.py b/py34/bacpypes/basetypes.py
index 339ffbf..a2cc055 100755
--- a/py34/bacpypes/basetypes.py
+++ b/py34/bacpypes/basetypes.py
@@ -10,7 +10,7 @@ from .debugging import ModuleLogger
 from .primitivedata import *
 from .constructeddata import *
 
-# some debuging
+# some debugging
 _debug = 0
 _log = ModuleLogger(globals())
 
diff --git a/py34/bacpypes/bsll.py b/py34/bacpypes/bsll.py
index a874c69..d81cd27 100755
--- a/py34/bacpypes/bsll.py
+++ b/py34/bacpypes/bsll.py
@@ -11,7 +11,7 @@ from .debugging import ModuleLogger, DebugContents, bacpypes_debugging
 
 from .pdu import *
 
-# some debuging
+# some debugging
 _debug = 0
 _log = ModuleLogger(globals())
 
diff --git a/py34/bacpypes/bsllservice.py b/py34/bacpypes/bsllservice.py
index c663b6c..f574dad 100755
--- a/py34/bacpypes/bsllservice.py
+++ b/py34/bacpypes/bsllservice.py
@@ -17,7 +17,7 @@ from .netservice import NetworkAdapter
 
 from .bsll import *
 
-# some debuging
+# some debugging
 _debug = 0
 _log = ModuleLogger(globals())
 
diff --git a/py34/bacpypes/bvll.py b/py34/bacpypes/bvll.py
index 5edd202..af79478 100755
--- a/py34/bacpypes/bvll.py
+++ b/py34/bacpypes/bvll.py
@@ -9,7 +9,7 @@ from .debugging import ModuleLogger, DebugContents, bacpypes_debugging
 
 from .pdu import *
 
-# some debuging
+# some debugging
 _debug = 0
 _log = ModuleLogger(globals())
 
diff --git a/py34/bacpypes/bvllservice.py b/py34/bacpypes/bvllservice.py
index 73bdc57..7134016 100755
--- a/py34/bacpypes/bvllservice.py
+++ b/py34/bacpypes/bvllservice.py
@@ -19,7 +19,7 @@ from .comm import Client, Server, bind, \
 
 from .bvll import *
 
-# some debuging
+# some debugging
 _debug = 0
 _log = ModuleLogger(globals())