diff --git a/.travis.yml b/.travis.yml
index 25b730ce..30233302 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,13 +4,11 @@ notifications:
 
 language: python
 python:
-  - "2.7"
   - "3.5"
 
 before_install:
   - pip install -r requirements.txt
   - pip install flake8
-  - pip install flake8-future-import
   - pip install --upgrade pytest
 
 install:
diff --git a/gem/__init__.py b/gem/__init__.py
index af1b768c..f1e77203 100644
--- a/gem/__init__.py
+++ b/gem/__init__.py
@@ -1,4 +1,2 @@
-from __future__ import absolute_import, print_function, division
-
 from gem.gem import *  # noqa
 from gem.optimise import select_expression  # noqa
diff --git a/gem/coffee.py b/gem/coffee.py
index c1afb774..be8a041e 100644
--- a/gem/coffee.py
+++ b/gem/coffee.py
@@ -4,9 +4,6 @@
 This file is NOT for code generation as a COFFEE AST.
 """
 
-from __future__ import absolute_import, print_function, division
-from six.moves import map, range
-
 from collections import OrderedDict
 import itertools
 import logging
diff --git a/gem/gem.py b/gem/gem.py
index 978f17ce..d5870ac9 100644
--- a/gem/gem.py
+++ b/gem/gem.py
@@ -14,10 +14,6 @@
 indices.
 """
 
-from __future__ import absolute_import, print_function, division
-from six import with_metaclass
-from six.moves import range, zip
-
 from abc import ABCMeta
 from itertools import chain
 from operator import attrgetter
@@ -57,7 +53,7 @@ def __call__(self, *args, **kwargs):
         return obj
 
 
-class Node(with_metaclass(NodeMeta, NodeBase)):
+class Node(NodeBase, metaclass=NodeMeta):
     """Abstract GEM node class."""
 
     __slots__ = ('free_indices',)
@@ -380,7 +376,7 @@ def __new__(cls, condition, then, else_):
         return self
 
 
-class IndexBase(with_metaclass(ABCMeta)):
+class IndexBase(metaclass=ABCMeta):
     """Abstract base class for indices."""
     pass
 
diff --git a/gem/impero.py b/gem/impero.py
index 3eee267e..c909e1bf 100644
--- a/gem/impero.py
+++ b/gem/impero.py
@@ -10,9 +10,6 @@
    (Command?) after clicking on them.
 """
 
-from __future__ import absolute_import, print_function, division
-from six import with_metaclass
-
 from abc import ABCMeta, abstractmethod
 
 from gem.node import Node as NodeBase
@@ -24,7 +21,7 @@ class Node(NodeBase):
     __slots__ = ()
 
 
-class Terminal(with_metaclass(ABCMeta, Node)):
+class Terminal(Node, metaclass=ABCMeta):
     """Abstract class for terminal Impero nodes"""
 
     __slots__ = ()
diff --git a/gem/impero_utils.py b/gem/impero_utils.py
index 43e739be..e5635975 100644
--- a/gem/impero_utils.py
+++ b/gem/impero_utils.py
@@ -6,14 +6,10 @@
 C code or a COFFEE AST.
 """
 
-from __future__ import absolute_import, print_function, division
-from six.moves import filter
-
 import collections
+from functools import singledispatch
 from itertools import chain, groupby
 
-from singledispatch import singledispatch
-
 from gem.node import traversal, collect_refcount
 from gem import gem, impero as imp, optimise, scheduling
 
diff --git a/gem/interpreter.py b/gem/interpreter.py
index a34ff577..a7e2e724 100644
--- a/gem/interpreter.py
+++ b/gem/interpreter.py
@@ -1,14 +1,11 @@
 """
 An interpreter for GEM trees.
 """
-from __future__ import absolute_import, print_function, division
-from six.moves import map
-
 import numpy
 import operator
 import math
 from collections import OrderedDict
-from singledispatch import singledispatch
+from functools import singledispatch
 import itertools
 
 from gem import gem, node
diff --git a/gem/node.py b/gem/node.py
index 6738381b..8345a0d6 100644
--- a/gem/node.py
+++ b/gem/node.py
@@ -1,9 +1,6 @@
 """Generic abstract node class and utility functions for creating
 expression DAG languages."""
 
-from __future__ import absolute_import, print_function, division
-from six.moves import map, zip
-
 import collections
 
 
diff --git a/gem/optimise.py b/gem/optimise.py
index d19006de..ebfffeee 100644
--- a/gem/optimise.py
+++ b/gem/optimise.py
@@ -1,15 +1,11 @@
 """A set of routines implementing various transformations on GEM
 expressions."""
 
-from __future__ import absolute_import, print_function, division
-from six.moves import filter, map, zip, zip_longest
-
 from collections import OrderedDict, defaultdict
-from functools import partial, reduce
-from itertools import combinations, permutations
+from functools import singledispatch, partial, reduce
+from itertools import combinations, permutations, zip_longest
 
 import numpy
-from singledispatch import singledispatch
 
 from gem.utils import groupby
 from gem.node import (Memoizer, MemoizerArg, reuse_if_untouched,
diff --git a/gem/refactorise.py b/gem/refactorise.py
index d3e2d4a7..1c65d11d 100644
--- a/gem/refactorise.py
+++ b/gem/refactorise.py
@@ -1,12 +1,9 @@
 """Data structures and algorithms for generic expansion and
 refactorisation."""
 
-from __future__ import absolute_import, print_function, division
-from six import iteritems
-from six.moves import intern, map
-
 from collections import Counter, OrderedDict, defaultdict, namedtuple
 from itertools import product
+from sys import intern
 
 from gem.node import Memoizer, traversal
 from gem.gem import Node, Zero, Product, Sum, Indexed, ListTensor, one
@@ -73,7 +70,7 @@ def add(self, sum_indices, atomics, rest):
         assert len(sum_indices) == len(sum_indices_set)
 
         atomics = tuple(atomics)
-        atomics_set = frozenset(iteritems(Counter(atomics)))
+        atomics_set = frozenset(Counter(atomics).items())
 
         assert isinstance(rest, Node)
 
@@ -83,7 +80,7 @@ def add(self, sum_indices, atomics, rest):
 
     def __iter__(self):
         """Iteration yields :py:class:`Monomial` objects"""
-        for key, (sum_indices, atomics) in iteritems(self.ordering):
+        for key, (sum_indices, atomics) in self.ordering.items():
             rest = self.monomials[key]
             yield Monomial(sum_indices, atomics, rest)
 
@@ -95,9 +92,9 @@ def sum(*args):
             assert isinstance(arg, MonomialSum)
             # Optimised implementation: no need to decompose and
             # reconstruct key.
-            for key, rest in iteritems(arg.monomials):
+            for key, rest in arg.monomials.items():
                 result.monomials[key] = Sum(result.monomials[key], rest)
-            for key, value in iteritems(arg.ordering):
+            for key, value in arg.ordering.items():
                 result.ordering.setdefault(key, value)
         return result
 
diff --git a/gem/scheduling.py b/gem/scheduling.py
index 767abce4..1fbb563c 100644
--- a/gem/scheduling.py
+++ b/gem/scheduling.py
@@ -1,8 +1,6 @@
 """Schedules operations to evaluate a multi-root expression DAG,
 forming an ordered list of Impero terminals."""
 
-from __future__ import absolute_import, print_function, division
-
 import collections
 import functools
 
diff --git a/gem/unconcatenate.py b/gem/unconcatenate.py
index 975b74c6..ce6e30b3 100644
--- a/gem/unconcatenate.py
+++ b/gem/unconcatenate.py
@@ -50,13 +50,10 @@
 unconcatenation, and then add up the results.
 """
 
-from __future__ import absolute_import, print_function, division
-from six.moves import map, range, zip
-
+from functools import singledispatch
 from itertools import chain
 
 import numpy
-from singledispatch import singledispatch
 
 from gem.node import Memoizer, reuse_if_untouched
 from gem.gem import (ComponentTensor, Concatenate, FlexiblyIndexed,
diff --git a/gem/utils.py b/gem/utils.py
index 1d7b62cc..12e0e0f6 100644
--- a/gem/utils.py
+++ b/gem/utils.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import, print_function, division
-from six import viewitems
-
 import collections
 
 
@@ -36,7 +33,7 @@ def groupby(iterable, key=None):
     groups = collections.OrderedDict()
     for elem in iterable:
         groups.setdefault(key(elem), []).append(elem)
-    return viewitems(groups)
+    return groups.items()
 
 
 def make_proxy_class(name, cls):
diff --git a/requirements-ext.txt b/requirements-ext.txt
index ce6ba245..24ce15ab 100644
--- a/requirements-ext.txt
+++ b/requirements-ext.txt
@@ -1,3 +1 @@
 numpy
-singledispatch
-six
diff --git a/setup.cfg b/setup.cfg
index 3179d526..12de4520 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,7 +1,3 @@
 [flake8]
-ignore =
-    E501,E226,E731,E741,
-    FI14,FI54,
-    FI50,FI51,FI53
+ignore = E501,E226,E731,E741
 exclude = .git,__pycache__,build,dist
-min-version = 2.7
diff --git a/setup.py b/setup.py
index 8a05e32c..e300a605 100644
--- a/setup.py
+++ b/setup.py
@@ -1,5 +1,3 @@
-from __future__ import print_function, division, absolute_import
-
 from distutils.core import setup
 
 version = "0.0.1"
diff --git a/tests/test_codegen.py b/tests/test_codegen.py
index b0694281..8d0bc796 100644
--- a/tests/test_codegen.py
+++ b/tests/test_codegen.py
@@ -1,5 +1,3 @@
-from __future__ import absolute_import, print_function, division
-
 import pytest
 
 from gem import impero_utils
diff --git a/tests/test_coffee_optimise.py b/tests/test_coffee_optimise.py
index bef6d825..065bb22e 100644
--- a/tests/test_coffee_optimise.py
+++ b/tests/test_coffee_optimise.py
@@ -1,5 +1,3 @@
-from __future__ import absolute_import, print_function, division
-
 import pytest
 
 from gem.gem import Index, Indexed, Product, Variable, Division, Literal, Sum
diff --git a/tests/test_create_fiat_element.py b/tests/test_create_fiat_element.py
index 259a0c8b..1fa2f437 100644
--- a/tests/test_create_fiat_element.py
+++ b/tests/test_create_fiat_element.py
@@ -1,4 +1,3 @@
-from __future__ import absolute_import, print_function, division
 import pytest
 
 import FIAT
diff --git a/tests/test_create_finat_element.py b/tests/test_create_finat_element.py
index 83c2b643..e135576d 100644
--- a/tests/test_create_finat_element.py
+++ b/tests/test_create_finat_element.py
@@ -1,4 +1,3 @@
-from __future__ import absolute_import, print_function, division
 import pytest
 
 import ufl
diff --git a/tests/test_delta_elimination.py b/tests/test_delta_elimination.py
index df76629f..3ac3f8dc 100644
--- a/tests/test_delta_elimination.py
+++ b/tests/test_delta_elimination.py
@@ -1,5 +1,3 @@
-from __future__ import absolute_import, print_function, division
-
 import pytest
 
 from gem.gem import Delta, Identity, Index, Indexed, one
diff --git a/tests/test_estimated_degree.py b/tests/test_estimated_degree.py
index d07cfeca..c3c80f02 100644
--- a/tests/test_estimated_degree.py
+++ b/tests/test_estimated_degree.py
@@ -1,4 +1,3 @@
-from __future__ import absolute_import, print_function, division
 import logging
 
 import pytest
diff --git a/tests/test_firedrake_972.py b/tests/test_firedrake_972.py
index b318233d..b8cc9922 100644
--- a/tests/test_firedrake_972.py
+++ b/tests/test_firedrake_972.py
@@ -1,4 +1,3 @@
-from __future__ import absolute_import, print_function, division
 import numpy
 import pytest
 
diff --git a/tests/test_flexibly_indexed.py b/tests/test_flexibly_indexed.py
index cd40b701..8390bceb 100644
--- a/tests/test_flexibly_indexed.py
+++ b/tests/test_flexibly_indexed.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import, print_function, division
-from six.moves import range
-
 from itertools import product
 
 import numpy
diff --git a/tests/test_gem_failure.py b/tests/test_gem_failure.py
index 03fb3521..8bf31338 100644
--- a/tests/test_gem_failure.py
+++ b/tests/test_gem_failure.py
@@ -1,4 +1,3 @@
-from __future__ import absolute_import, print_function, division
 from ufl import (triangle, tetrahedron, FiniteElement,
                  TrialFunction, TestFunction, inner, grad, dx, dS)
 from tsfc import compile_form
diff --git a/tests/test_geometry.py b/tests/test_geometry.py
index 6c36ce13..458f1b56 100644
--- a/tests/test_geometry.py
+++ b/tests/test_geometry.py
@@ -1,5 +1,3 @@
-from __future__ import absolute_import, print_function, division
-
 import pytest
 import numpy as np
 
diff --git a/tests/test_idempotency.py b/tests/test_idempotency.py
index e5ce04dd..7656592e 100644
--- a/tests/test_idempotency.py
+++ b/tests/test_idempotency.py
@@ -1,4 +1,3 @@
-from __future__ import absolute_import, print_function, division
 import ufl
 from tsfc import compile_form
 import pytest
diff --git a/tests/test_pickle_gem.py b/tests/test_pickle_gem.py
index 4d484a98..73e39cac 100644
--- a/tests/test_pickle_gem.py
+++ b/tests/test_pickle_gem.py
@@ -1,5 +1,4 @@
-from __future__ import absolute_import, print_function, division
-from six.moves import cPickle as pickle, range
+import pickle
 import gem
 import numpy
 import pytest
diff --git a/tests/test_refactorise.py b/tests/test_refactorise.py
index c12747ea..8c8251df 100644
--- a/tests/test_refactorise.py
+++ b/tests/test_refactorise.py
@@ -1,5 +1,3 @@
-from __future__ import absolute_import, print_function, division
-
 from functools import partial
 
 import pytest
diff --git a/tests/test_simplification.py b/tests/test_simplification.py
index 6df0be43..e5fe3d66 100644
--- a/tests/test_simplification.py
+++ b/tests/test_simplification.py
@@ -1,5 +1,3 @@
-from __future__ import absolute_import, print_function, division
-
 import pytest
 
 from gem.gem import Variable, Zero, Conditional, \
diff --git a/tests/test_sum_factorisation.py b/tests/test_sum_factorisation.py
index 0b36d4df..9e31b125 100644
--- a/tests/test_sum_factorisation.py
+++ b/tests/test_sum_factorisation.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import, print_function, division
-from six.moves import range
-
 import numpy
 import pytest
 
diff --git a/tests/test_tensor.py b/tests/test_tensor.py
index c3e8950e..f13ea79b 100644
--- a/tests/test_tensor.py
+++ b/tests/test_tensor.py
@@ -1,5 +1,3 @@
-from __future__ import absolute_import, print_function, division
-
 import numpy
 import pytest
 
diff --git a/tests/test_underintegration.py b/tests/test_underintegration.py
index 9bd2cc1c..6d7846fb 100644
--- a/tests/test_underintegration.py
+++ b/tests/test_underintegration.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import, print_function, division
-from six.moves import range
-
 from functools import reduce
 
 import numpy
diff --git a/tsfc/__init__.py b/tsfc/__init__.py
index da4cbbfa..e69abac5 100644
--- a/tsfc/__init__.py
+++ b/tsfc/__init__.py
@@ -1,5 +1,3 @@
-from __future__ import absolute_import, print_function, division
-
 from tsfc.driver import compile_form, compile_expression_at_points  # noqa: F401
 from tsfc.parameters import default_parameters  # noqa: F401
 
diff --git a/tsfc/coffee.py b/tsfc/coffee.py
index 0bae0591..915e60e5 100644
--- a/tsfc/coffee.py
+++ b/tsfc/coffee.py
@@ -2,15 +2,12 @@
 
 This is the final stage of code generation in TSFC."""
 
-from __future__ import absolute_import, print_function, division
-
 from collections import defaultdict
-from functools import reduce
+from functools import singledispatch, reduce
 from math import isnan
 import itertools
 
 import numpy
-from singledispatch import singledispatch
 
 import coffee.base as coffee
 
diff --git a/tsfc/coffee_mode.py b/tsfc/coffee_mode.py
index 2dc62174..025a9b34 100644
--- a/tsfc/coffee_mode.py
+++ b/tsfc/coffee_mode.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import, print_function, division
-from six.moves import zip
-
 from functools import partial, reduce
 
 from gem.node import traversal
diff --git a/tsfc/driver.py b/tsfc/driver.py
index 8e74f4ff..e09aef10 100644
--- a/tsfc/driver.py
+++ b/tsfc/driver.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import, print_function, division
-from six import iterkeys, iteritems, viewitems
-from six.moves import range, zip
-
 import collections
 import operator
 import string
@@ -186,8 +182,8 @@ def compile_integral(integral_data, form_data, prefix, parameters,
 
     # Finalise mode representations into a set of assignments
     assignments = []
-    for mode, var_reps in iteritems(mode_irs):
-        assignments.extend(mode.flatten(viewitems(var_reps), index_cache))
+    for mode, var_reps in mode_irs.items():
+        assignments.extend(mode.flatten(var_reps.items(), index_cache))
 
     if assignments:
         return_variables, expressions = zip(*assignments)
@@ -197,8 +193,8 @@ def compile_integral(integral_data, form_data, prefix, parameters,
 
     # Need optimised roots for COFFEE
     options = dict(reduce(operator.and_,
-                          [viewitems(mode.finalise_options)
-                           for mode in iterkeys(mode_irs)]))
+                          [mode.finalise_options.items()
+                           for mode in mode_irs.keys()]))
     expressions = impero_utils.preprocess_gem(expressions, **options)
     assignments = list(zip(return_variables, expressions))
 
diff --git a/tsfc/fem.py b/tsfc/fem.py
index d21ed1ea..6e7a9ece 100644
--- a/tsfc/fem.py
+++ b/tsfc/fem.py
@@ -1,15 +1,11 @@
 """Functions to translate UFL finite element objects and reference
 geometric quantities into GEM expressions."""
 
-from __future__ import absolute_import, print_function, division
-from six import iterkeys, iteritems, itervalues
-from six.moves import map, range, zip
-
 import collections
 import itertools
+from functools import singledispatch
 
 import numpy
-from singledispatch import singledispatch
 
 import ufl
 from ufl.corealg.map_dag import map_expr_dag, map_expr_dags
@@ -397,17 +393,17 @@ def translate_cell_edge_vectors(terminal, mt, ctx):
         gem.Sum(gem.Indexed(cell_vertices, (u, c)),
                 gem.Product(gem.Literal(-1),
                             gem.Indexed(cell_vertices, (v, c))))
-        for _, (u, v) in sorted(iteritems(ctx.fiat_cell.get_topology()[1]))
+        for _, (u, v) in sorted(ctx.fiat_cell.get_topology()[1].items())
     ])
     return gem.ComponentTensor(gem.Indexed(expr, (e,)), (e, c))
 
 
 def fiat_to_ufl(fiat_dict, order):
     # All derivative multiindices must be of the same dimension.
-    dimension, = list(set(len(alpha) for alpha in iterkeys(fiat_dict)))
+    dimension, = set(len(alpha) for alpha in fiat_dict.keys())
 
     # All derivative tables must have the same shape.
-    shape, = list(set(table.shape for table in itervalues(fiat_dict)))
+    shape, = set(table.shape for table in fiat_dict.values())
     sigma = tuple(gem.Index(extent=extent) for extent in shape)
 
     # Convert from FIAT to UFL format
@@ -434,7 +430,7 @@ def callback(entity_id):
         finat_dict = ctx.basis_evaluation(element, mt.local_derivatives, entity_id)
         # Filter out irrelevant derivatives
         filtered_dict = {alpha: table
-                         for alpha, table in iteritems(finat_dict)
+                         for alpha, table in finat_dict.items()
                          if sum(alpha) == mt.local_derivatives}
 
         # Change from FIAT to UFL arrangement
@@ -461,7 +457,7 @@ def translate_coefficient(terminal, mt, ctx):
     per_derivative = collections.defaultdict(list)
     for entity_id in ctx.entity_ids:
         finat_dict = ctx.basis_evaluation(element, mt.local_derivatives, entity_id)
-        for alpha, table in iteritems(finat_dict):
+        for alpha, table in finat_dict.items():
             # Filter out irrelevant derivatives
             if sum(alpha) == mt.local_derivatives:
                 # A numerical hack that FFC used to apply on FIAT
@@ -476,11 +472,11 @@ def take_singleton(xs):
             x, = xs  # asserts singleton
             return x
         per_derivative = {alpha: take_singleton(tables)
-                          for alpha, tables in iteritems(per_derivative)}
+                          for alpha, tables in per_derivative.items()}
     else:
         f = ctx.entity_number(mt.restriction)
         per_derivative = {alpha: gem.select_expression(tables, f)
-                          for alpha, tables in iteritems(per_derivative)}
+                          for alpha, tables in per_derivative.items()}
 
     # Coefficient evaluation
     ctx.index_cache.setdefault(terminal.ufl_element(), element.get_indices())
@@ -488,7 +484,7 @@ def take_singleton(xs):
     zeta = element.get_value_indices()
     vec_beta, = gem.optimise.remove_componenttensors([gem.Indexed(vec, beta)])
     value_dict = {}
-    for alpha, table in iteritems(per_derivative):
+    for alpha, table in per_derivative.items():
         table_qi = gem.Indexed(table, beta + zeta)
         summands = []
         for var, expr in unconcatenate([(vec_beta, table_qi)], ctx.index_cache):
diff --git a/tsfc/fiatinterface.py b/tsfc/fiatinterface.py
index 6cf579c1..c106cbcc 100644
--- a/tsfc/fiatinterface.py
+++ b/tsfc/fiatinterface.py
@@ -21,10 +21,7 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with FFC. If not, see <http://www.gnu.org/licenses/>.
 
-from __future__ import absolute_import, print_function, division
-
-from singledispatch import singledispatch
-from functools import partial
+from functools import singledispatch, partial
 import weakref
 
 import FIAT
diff --git a/tsfc/finatinterface.py b/tsfc/finatinterface.py
index 0a794b38..6529ce3b 100644
--- a/tsfc/finatinterface.py
+++ b/tsfc/finatinterface.py
@@ -21,10 +21,7 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with FFC. If not, see <http://www.gnu.org/licenses/>.
 
-from __future__ import absolute_import, print_function, division
-from six import iteritems
-
-from singledispatch import singledispatch
+from functools import singledispatch
 import weakref
 
 import finat
@@ -227,7 +224,7 @@ def _create_element(ufl_element, **kwargs):
         _cache[ufl_element] = {}
         cache = _cache[ufl_element]
 
-    for key, finat_element in iteritems(cache):
+    for key, finat_element in cache.items():
         # Cache hit if all relevant parameter values match.
         if all(kwargs[param] == value for param, value in key):
             return finat_element, set(param for param, value in key)
diff --git a/tsfc/kernel_interface/__init__.py b/tsfc/kernel_interface/__init__.py
index 0eb52be7..0ff4b6e9 100644
--- a/tsfc/kernel_interface/__init__.py
+++ b/tsfc/kernel_interface/__init__.py
@@ -1,12 +1,9 @@
-from __future__ import absolute_import, print_function, division
-from six import with_metaclass
-
 from abc import ABCMeta, abstractmethod
 
 from gem.utils import make_proxy_class
 
 
-class KernelInterface(with_metaclass(ABCMeta)):
+class KernelInterface(metaclass=ABCMeta):
     """Abstract interface for accessing the GEM expressions corresponding
     to kernel arguments."""
 
diff --git a/tsfc/kernel_interface/common.py b/tsfc/kernel_interface/common.py
index b3fee316..bf9fd4c1 100644
--- a/tsfc/kernel_interface/common.py
+++ b/tsfc/kernel_interface/common.py
@@ -1,5 +1,3 @@
-from __future__ import absolute_import, print_function, division
-
 import numpy
 
 import coffee.base as coffee
diff --git a/tsfc/kernel_interface/firedrake.py b/tsfc/kernel_interface/firedrake.py
index 36fd2293..597f16fc 100644
--- a/tsfc/kernel_interface/firedrake.py
+++ b/tsfc/kernel_interface/firedrake.py
@@ -1,5 +1,3 @@
-from __future__ import absolute_import, print_function, division
-
 import numpy
 from collections import namedtuple
 from itertools import chain, product
diff --git a/tsfc/kernel_interface/ufc.py b/tsfc/kernel_interface/ufc.py
index 9c9b1435..c0f2ca79 100644
--- a/tsfc/kernel_interface/ufc.py
+++ b/tsfc/kernel_interface/ufc.py
@@ -1,6 +1,3 @@
-from __future__ import absolute_import, print_function, division
-from six.moves import range, zip
-
 import numpy
 import functools
 from itertools import chain, product
diff --git a/tsfc/logging.py b/tsfc/logging.py
index e0648389..6bced525 100644
--- a/tsfc/logging.py
+++ b/tsfc/logging.py
@@ -1,7 +1,5 @@
 """Logging for TSFC."""
 
-from __future__ import absolute_import, print_function, division
-
 import logging
 
 logger = logging.getLogger('tsfc')
diff --git a/tsfc/modified_terminals.py b/tsfc/modified_terminals.py
index 006124f2..1cbf41f4 100644
--- a/tsfc/modified_terminals.py
+++ b/tsfc/modified_terminals.py
@@ -20,8 +20,6 @@
 
 """Definitions of 'modified terminals', a core concept in uflacs."""
 
-from __future__ import absolute_import, print_function, division
-
 from ufl.classes import (ReferenceValue, ReferenceGrad,
                          NegativeRestricted, PositiveRestricted,
                          Restricted, FacetAvg, CellAvg, ConstantValue,
diff --git a/tsfc/parameters.py b/tsfc/parameters.py
index 51893807..70dc647d 100644
--- a/tsfc/parameters.py
+++ b/tsfc/parameters.py
@@ -1,5 +1,3 @@
-from __future__ import absolute_import, print_function, division
-
 import numpy
 
 
diff --git a/tsfc/spectral.py b/tsfc/spectral.py
index 96f59948..3db58c46 100644
--- a/tsfc/spectral.py
+++ b/tsfc/spectral.py
@@ -1,9 +1,6 @@
-from __future__ import absolute_import, print_function, division
-from six.moves import zip, zip_longest
-
 from collections import OrderedDict, defaultdict, namedtuple
 from functools import partial, reduce
-from itertools import chain
+from itertools import chain, zip_longest
 
 from gem.gem import Delta, Indexed, Sum, index_sum, one
 from gem.optimise import delta_elimination as _delta_elimination
diff --git a/tsfc/tensor.py b/tsfc/tensor.py
index a9f1ad17..d4f80fa0 100644
--- a/tsfc/tensor.py
+++ b/tsfc/tensor.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import, print_function, division
-from six import iteritems
-from six.moves import zip
-
 from collections import defaultdict
 from functools import partial, reduce
 from itertools import count
@@ -39,7 +35,7 @@ def einsum(factors, sum_indices):
         subscript_parts.append(''.join(letters))
 
     result_pairs = sorted((letter, index)
-                          for index, letter in iteritems(index2letter)
+                          for index, letter in index2letter.items()
                           if index not in sum_indices)
 
     subscripts = ','.join(subscript_parts) + '->' + ''.join(l for l, i in result_pairs)
diff --git a/tsfc/ufl2gem.py b/tsfc/ufl2gem.py
index f739e0dc..33b50723 100644
--- a/tsfc/ufl2gem.py
+++ b/tsfc/ufl2gem.py
@@ -1,7 +1,5 @@
 """Translation of UFL tensor-algebra into GEM tensor-algebra."""
 
-from __future__ import absolute_import, print_function, division
-
 import collections
 import ufl
 
diff --git a/tsfc/ufl_utils.py b/tsfc/ufl_utils.py
index bc53419e..e8575347 100644
--- a/tsfc/ufl_utils.py
+++ b/tsfc/ufl_utils.py
@@ -1,9 +1,8 @@
 """Utilities for preprocessing UFL objects."""
 
-from __future__ import absolute_import, print_function, division
+from functools import singledispatch
 
 import numpy
-from singledispatch import singledispatch
 
 import ufl
 from ufl import as_tensor, indices, replace
diff --git a/tsfc/vanilla.py b/tsfc/vanilla.py
index c995e162..ecf24cd5 100644
--- a/tsfc/vanilla.py
+++ b/tsfc/vanilla.py
@@ -1,5 +1,3 @@
-from __future__ import absolute_import, print_function, division
-
 from functools import reduce
 
 from gem import index_sum, Sum