diff --git a/GraphicsScene/mouseEvents.py b/GraphicsScene/mouseEvents.py
index bb24b758..0b71ac6f 100644
--- a/GraphicsScene/mouseEvents.py
+++ b/GraphicsScene/mouseEvents.py
@@ -3,7 +3,7 @@ from pyqtgraph.Qt import QtCore, QtGui
 import weakref
 import pyqtgraph.ptime as ptime
 
-class MouseDragEvent:
+class MouseDragEvent(object):
     """
     Instances of this class are delivered to items in a :class:`GraphicsScene <pyqtgraph.GraphicsScene>` via their mouseDragEvent() method when the item is being mouse-dragged. 
     
@@ -144,7 +144,7 @@ class MouseDragEvent:
 
 
 
-class MouseClickEvent:
+class MouseClickEvent(object):
     """
     Instances of this class are delivered to items in a :class:`GraphicsScene <pyqtgraph.GraphicsScene>` via their mouseClickEvent() method when the item is clicked. 
     
@@ -229,7 +229,7 @@ class MouseClickEvent:
 
 
 
-class HoverEvent:
+class HoverEvent(object):
     """
     Instances of this class are delivered to items in a :class:`GraphicsScene <pyqtgraph.GraphicsScene>` via their hoverEvent() method when the mouse is hovering over the item.
     This event class both informs items that the mouse cursor is nearby and allows items to 
diff --git a/debug.py b/debug.py
index ba1eb4ed..ea9157aa 100644
--- a/debug.py
+++ b/debug.py
@@ -317,7 +317,7 @@ def objectSize(obj, ignore=None, verbose=False, depth=0, recursive=False):
                     #print indent + '  -', k, len(refs)
     return size
 
-class GarbageWatcher:
+class GarbageWatcher(object):
     """
     Convenient dictionary for holding weak references to objects.
     Mainly used to check whether the objects have been collect yet or not.
@@ -356,7 +356,7 @@ class GarbageWatcher:
         return self.objs[item]
 
     
-class Profiler:
+class Profiler(object):
     """Simple profiler allowing measurement of multiple time intervals.
     
     Example:
@@ -451,7 +451,7 @@ def lookup(oid, objects=None):
         
                     
         
-class ObjTracker:
+class ObjTracker(object):
     """
     Tracks all objects under the sun, reporting the changes between snapshots: what objects are created, deleted, and persistent.
     This class is very useful for tracking memory leaks. The class goes to great (but not heroic) lengths to avoid tracking 
diff --git a/exceptionHandling.py b/exceptionHandling.py
index 71d538c6..daa821b7 100644
--- a/exceptionHandling.py
+++ b/exceptionHandling.py
@@ -47,7 +47,7 @@ def setTracebackClearing(clear=True):
     global clear_tracebacks
     clear_tracebacks = clear
     
-class ExceptionHandler:
+class ExceptionHandler(object):
     def __call__(self, *args):
         ## call original exception handler first (prints exception)
         global original_excepthook, callbacks, clear_tracebacks
diff --git a/flowchart/Terminal.py b/flowchart/Terminal.py
index 44487d04..18ff12c1 100644
--- a/flowchart/Terminal.py
+++ b/flowchart/Terminal.py
@@ -7,7 +7,7 @@ from pyqtgraph.Point import Point
 #from PySide import QtCore, QtGui
 from .eq import *
 
-class Terminal:
+class Terminal(object):
     def __init__(self, node, name, io, optional=False, multi=False, pos=None, renamable=False, removable=False, multiable=False, bypass=None):
         """
         Construct a new terminal. 
diff --git a/graphicsItems/GraphicsWidgetAnchor.py b/graphicsItems/GraphicsWidgetAnchor.py
index b71e781a..9770b661 100644
--- a/graphicsItems/GraphicsWidgetAnchor.py
+++ b/graphicsItems/GraphicsWidgetAnchor.py
@@ -2,7 +2,7 @@ from ..Qt import QtGui, QtCore
 from ..Point import Point
 
 
-class GraphicsWidgetAnchor:
+class GraphicsWidgetAnchor(object):
     """
     Class used to allow GraphicsWidgets to anchor to a specific position on their
     parent. 
diff --git a/graphicsItems/ScatterPlotItem.py b/graphicsItems/ScatterPlotItem.py
index 6e442a1d..f0dcfb60 100644
--- a/graphicsItems/ScatterPlotItem.py
+++ b/graphicsItems/ScatterPlotItem.py
@@ -77,7 +77,7 @@ def makeSymbolPixmap(size, pen, brush, symbol):
     img = renderSymbol(symbol, size, pen, brush)
     return QtGui.QPixmap(img)
     
-class SymbolAtlas:
+class SymbolAtlas(object):
     """
     Used to efficiently construct a single QPixmap containing all rendered symbols
     for a ScatterPlotItem. This is required for fragment rendering.
diff --git a/metaarray/MetaArray.py b/metaarray/MetaArray.py
index 5076dd53..ec1abd3c 100644
--- a/metaarray/MetaArray.py
+++ b/metaarray/MetaArray.py
@@ -48,7 +48,7 @@ def axis(name=None, cols=None, values=None, units=None):
             ax['cols'].append(col)
     return ax
 
-class sliceGenerator:
+class sliceGenerator(object):
     """Just a compact way to generate tuples of slice objects."""
     def __getitem__(self, arg):
         return arg
diff --git a/multiprocess/parallelizer.py b/multiprocess/parallelizer.py
index 96a766c1..0d5d6f5c 100644
--- a/multiprocess/parallelizer.py
+++ b/multiprocess/parallelizer.py
@@ -6,7 +6,7 @@ class CanceledError(Exception):
     """Raised when the progress dialog is canceled during a processing operation."""
     pass
 
-class Parallelize:
+class Parallelize(object):
     """
     Class for ultra-simple inline parallelization on multi-core CPUs
     
@@ -233,7 +233,7 @@ class Parallelize:
         self.progress[pid].append(i)
     
     
-class Tasker:
+class Tasker(object):
     def __init__(self, parallelizer, process, tasks, kwds):
         self.proc = process
         self.par = parallelizer
diff --git a/multiprocess/remoteproxy.py b/multiprocess/remoteproxy.py
index 4f13b5c6..f8da1bd7 100644
--- a/multiprocess/remoteproxy.py
+++ b/multiprocess/remoteproxy.py
@@ -431,7 +431,7 @@ class RemoteEventHandler(object):
         return LocalObjectProxy(obj)
         
         
-class Request:
+class Request(object):
     """
     Request objects are returned when calling an ObjectProxy in asynchronous mode
     or if a synchronous call has timed out. Use hasResult() to ask whether
diff --git a/opengl/shaders.py b/opengl/shaders.py
index e9a4af9d..1799b648 100644
--- a/opengl/shaders.py
+++ b/opengl/shaders.py
@@ -209,7 +209,7 @@ CompiledShaderPrograms = {}
 def getShaderProgram(name):
     return ShaderProgram.names[name]
 
-class Shader:
+class Shader(object):
     def __init__(self, shaderType, code):
         self.shaderType = shaderType
         self.code = code
@@ -260,7 +260,7 @@ class FragmentShader(Shader):
         
         
 
-class ShaderProgram:
+class ShaderProgram(object):
     names = {}
     
     def __init__(self, name, shaders, uniforms=None):
diff --git a/parametertree/Parameter.py b/parametertree/Parameter.py
index e84bcebe..c8ed4902 100644
--- a/parametertree/Parameter.py
+++ b/parametertree/Parameter.py
@@ -665,7 +665,7 @@ class Parameter(QtCore.QObject):
             self.sigTreeStateChanged.emit(self, changes)
 
 
-class SignalBlocker:
+class SignalBlocker(object):
     def __init__(self, enterFn, exitFn):
         self.enterFn = enterFn
         self.exitFn = exitFn
diff --git a/pgcollections.py b/pgcollections.py
index be5281f2..b0198526 100644
--- a/pgcollections.py
+++ b/pgcollections.py
@@ -260,7 +260,7 @@ def makeThreadsafe(obj):
         raise Exception("Not sure how to make object of type %s thread-safe" % str(type(obj)))
         
         
-class Locker:
+class Locker(object):
     def __init__(self, lock):
         self.lock = lock
         self.lock.acquire()
diff --git a/widgets/BusyCursor.py b/widgets/BusyCursor.py
index 4212d6a6..b013dda0 100644
--- a/widgets/BusyCursor.py
+++ b/widgets/BusyCursor.py
@@ -2,7 +2,7 @@ from pyqtgraph.Qt import QtGui, QtCore
 
 __all__ = ['BusyCursor']
 
-class BusyCursor:
+class BusyCursor(object):
     """Class for displaying a busy mouse cursor during long operations.
     Usage::