diff --git a/src/Ophis/Environment.py b/src/Ophis/Environment.py
index 533be44..0450262 100644
--- a/src/Ophis/Environment.py
+++ b/src/Ophis/Environment.py
@@ -9,7 +9,7 @@
 
 import Ophis.Errors as Err
 
-class Environment:
+class Environment(object):
     """Environment class.
     Controls the various scopes and global abstract execution variables."""
     def __init__(self):
diff --git a/src/Ophis/Frontend.py b/src/Ophis/Frontend.py
index 4313c57..38c03a9 100644
--- a/src/Ophis/Frontend.py
+++ b/src/Ophis/Frontend.py
@@ -13,7 +13,7 @@ import os
 # You may use, modify, and distribute this file under the MIT
 # license: See README for details.
 
-class Lexeme:
+class Lexeme(object):
     "Class for lexer tokens.  Used by lexer and parser."
     def __init__(self, type="UNKNOWN", value=None):
         self.type = type.upper()
@@ -137,7 +137,7 @@ def lex(point, line):
     add_EOL()
     return result
 
-class ParseLine:
+class ParseLine(object):
     "Maintains the parse state of a line of code.  Enables arbitrary lookahead."
     def __init__(self, lexemes):
         self.lexemes = lexemes
diff --git a/src/Ophis/IR.py b/src/Ophis/IR.py
index 6e017f6..40fe818 100644
--- a/src/Ophis/IR.py
+++ b/src/Ophis/IR.py
@@ -9,7 +9,7 @@
 
 import Ophis.Errors as Err
 
-class Node:
+class Node(object):
     """The default IR Node
     Instances of Node always have the three fields ppt(Program Point),
     nodetype(a string), and data (a list)."""
@@ -38,7 +38,7 @@ NullNode = Node("<none>", "None")
 def SequenceNode(ppt, nodelist):
     return Node(ppt, "SEQUENCE", *nodelist)
 
-class Expr:
+class Expr(object):
     """Base class for Ophis expressions
     All expressions have a field called "data" and a boolean field
     called "hardcoded".  An expression is hardcoded if it has no
diff --git a/src/Ophis/Passes.py b/src/Ophis/Passes.py
index 8565e55..497f37e 100644
--- a/src/Ophis/Passes.py
+++ b/src/Ophis/Passes.py
@@ -20,7 +20,7 @@ import Ophis.Macro as Macro
 
 # The passes themselves
 
-class Pass:
+class Pass(object):
     """Superclass for all assembler passes.  Automatically handles IR
     types that modify the environent's structure, and by default
     raises an error on anything else.  Override visitUnknown in your
@@ -67,7 +67,7 @@ class Pass:
                 print>>sys.stderr, "Current IR:"
                 print>>sys.stderr, node
 
-class FixPoint:
+class FixPoint(object):
     """A specialized class that is not a pass but can be run like one.
     This class takes a list of passes and a "fixpoint" function."""
     def __init__(self, name, passes, fixpoint):