diff --git a/codepy/bpl.py b/codepy/bpl.py
index 1e09c9f..bf39830 100644
--- a/codepy/bpl.py
+++ b/codepy/bpl.py
@@ -58,7 +58,7 @@ def expose_vector_type(self, name, py_name=None):
         if py_name is None:
             py_name = name
 
-        from cgen import (Block, Typedef, Line, Statement, Value)
+        from cgen import Block, Line, Statement, Typedef, Value
 
         self.init_body.append(
             Block([
@@ -134,8 +134,7 @@ def generate(self):
         module line-by-line.
         """
 
-        from cgen import Block, Module, Include, Line, Define, \
-                PrivateNamespace
+        from cgen import Block, Define, Include, Line, Module, PrivateNamespace
 
         body = []
 
diff --git a/codepy/cuda.py b/codepy/cuda.py
index c9b7b0d..58de7d3 100644
--- a/codepy/cuda.py
+++ b/codepy/cuda.py
@@ -1,4 +1,6 @@
 import cgen
+
+
 """Convenience interface for using CodePy with CUDA"""
 
 
@@ -70,8 +72,7 @@ def compile(self, host_toolchain, nvcc_toolchain,
         host_code = "{}\n".format(self.boost_module.generate())
         device_code = "{}\n".format(self.generate())
 
-        from codepy.jit import compile_from_string
-        from codepy.jit import link_extension
+        from codepy.jit import compile_from_string, link_extension
 
         local_host_kwargs = kwargs.copy()
         local_host_kwargs.update(host_kwargs)
diff --git a/codepy/elementwise.py b/codepy/elementwise.py
index 3401b3b..1d882c1 100644
--- a/codepy/elementwise.py
+++ b/codepy/elementwise.py
@@ -4,10 +4,11 @@
 __copyright__ = "Copyright (C) 2009 Andreas Kloeckner"
 
 
-from pytools import memoize
 import numpy
 from cgen import POD, Value, dtype_to_ctype
 
+from pytools import memoize
+
 
 class Argument:
     def __init__(self, dtype, name):
@@ -46,11 +47,11 @@ def struct_char(self):
 
 
 def get_elwise_module_descriptor(arguments, operation, name="kernel"):
-    from codepy.bpl import BoostPythonModule
+    from cgen import (
+        POD, Block, For, FunctionBody, FunctionDeclaration, Include, Initializer,
+        Line, Statement, Struct, Value)
 
-    from cgen import FunctionBody, FunctionDeclaration, \
-            Value, POD, Struct, For, Initializer, Include, Statement, \
-            Line, Block
+    from codepy.bpl import BoostPythonModule
 
     S = Statement  # noqa: N806
 
diff --git a/codepy/jit.py b/codepy/jit.py
index c1fcb87..136713a 100644
--- a/codepy/jit.py
+++ b/codepy/jit.py
@@ -26,15 +26,18 @@
 THE SOFTWARE.
 """
 
+import logging
+from dataclasses import dataclass
+from typing import List, NamedTuple
+
 from codepy import CompileError
-from pytools import Record
 
-import logging
+
 logger = logging.getLogger(__name__)
 
 
 def _erase_dir(dir):
-    from os import listdir, unlink, rmdir
+    from os import listdir, rmdir, unlink
     from os.path import join
     for name in listdir(dir):
         unlink(join(dir, name))
@@ -211,8 +214,16 @@ class _InvalidInfoFile(RuntimeError):
     pass
 
 
-class _SourceInfo(Record):
-    pass
+class _Dependency(NamedTuple):
+    name: str
+    mtime: int
+    md5: str
+
+
+@dataclass(frozen=True)
+class _SourceInfo:
+    dependencies: List[NamedTuple]
+    source_name: str
 
 
 def compile_from_string(toolchain, name, source_string,
@@ -308,10 +319,9 @@ def get_file_md5sum(fname):
         return checksum.hexdigest()
 
     def get_dep_structure(source_paths):
-        deps = list(toolchain.get_dependencies(source_paths))
-        deps.sort()
-        return [(dep, os.stat(dep).st_mtime, get_file_md5sum(dep)) for dep in deps
-                if dep not in source_paths]
+        deps = toolchain.get_dependencies(source_paths)
+        return [_Dependency(dep, os.stat(dep).st_mtime, get_file_md5sum(dep))
+                for dep in sorted(deps) if dep not in source_paths]
 
     def write_source(name):
         for i, source in enumerate(source_string):
@@ -479,6 +489,8 @@ def link_extension(toolchain, objects, mod_name, cache_dir=None,
 
 
 from pytools import MovedFunctionDeprecationWrapper  # noqa: E402
+
 from codepy.toolchain import guess_toolchain as _gtc  # noqa: E402
 
+
 guess_toolchain = MovedFunctionDeprecationWrapper(_gtc)
diff --git a/codepy/libraries.py b/codepy/libraries.py
index 9723cff..125408b 100644
--- a/codepy/libraries.py
+++ b/codepy/libraries.py
@@ -10,8 +10,8 @@ def search_on_path(filenames):
     """Find file on system path."""
     # http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/52224
 
-    from os.path import exists, join, abspath
-    from os import pathsep, environ
+    from os import environ, pathsep
+    from os.path import abspath, exists, join
 
     search_path = environ["PATH"]
 
diff --git a/codepy/toolchain.py b/codepy/toolchain.py
index c4f8d56..624d7a8 100644
--- a/codepy/toolchain.py
+++ b/codepy/toolchain.py
@@ -1,6 +1,5 @@
 """Toolchains for Just-in-time Python extension compilation."""
 
-
 __copyright__ = """
 "Copyright (C) 2008,9 Andreas Kloeckner, Bryan Catanzaro
 """
@@ -25,28 +24,40 @@
 THE SOFTWARE.
 """
 
+from abc import ABC, abstractmethod
+from dataclasses import dataclass, replace
+from typing import AbstractSet, Any, List
 
 from codepy import CompileError
-from pytools import Record
 
 
-class Toolchain(Record):
+@dataclass(frozen=True)
+class Toolchain(ABC):
     """Abstract base class for tools used to link dynamic Python modules."""
 
-    def __init__(self, *args, **kwargs):
-        if "features" not in kwargs:
-            kwargs["features"] = set()
-        Record.__init__(self, *args, **kwargs)
+    #: A list of directories where libraries are found.
+    library_dirs: List[str]
+    #: A list of libraries used.
+    libraries: List[str]
+    #: A list of directories from which to include header files.
+    include_dirs: List[str]
+
+    features: AbstractSet[str]
+
+    def copy(self, **kwargs: Any) -> "Toolchain":
+        from warnings import warn
+        warn(f"'{type(self).__name__}.copy' is deprecated. This is now a "
+             "dataclass and should be used with the standard 'replace'.",
+             DeprecationWarning, stacklevel=2)
+
+        return replace(self, **kwargs)
 
+    @abstractmethod
     def get_version(self):
         """Return a string describing the exact version of the tools (compilers etc.)
         involved in this toolchain.
-
-        Implemented by subclasses.
         """
 
-        raise NotImplementedError
-
     def abi_id(self):
         """Return a picklable Python object that describes the ABI (Python version,
         compiler versions, etc.) against which a Python module is compiled.
@@ -80,50 +91,38 @@ def add_library(self, feature, include_dirs, library_dirs, libraries):
 
         self.libraries = libraries + self.libraries
 
+    @abstractmethod
     def get_dependencies(self,  source_files):
-        """Return a list of header files referred to by *source_files.
-
-        Implemented by subclasses.
-        """
-
-        raise NotImplementedError
+        """Return a list of header files referred to by *source_files*."""
 
+    @abstractmethod
     def build_extension(self, ext_file, source_files, debug=False):
         """Create the extension file *ext_file* from *source_files*
         by invoking the toolchain. Raise :exc:`~codepy.jit.CompileError` in
         case of error.
 
         If *debug* is True, print the commands executed.
-
-        Implemented by subclasses.
         """
 
-        raise NotImplementedError
-
+    @abstractmethod
     def build_object(self, obj_file, source_files, debug=False):
         """Build a compiled object *obj_file* from *source_files*
         by invoking the toolchain. Raise :exc:`CompileError` in
         case of error.
 
         If *debug* is True, print the commands executed.
-
-        Implemented by subclasses.
         """
 
-        raise NotImplementedError
-
+    @abstractmethod
     def link_extension(self, ext_file, object_files, debug=False):
         """Create the extension file *ext_file* from *object_files*
         by invoking the toolchain. Raise :exc:`CompileError` in
         case of error.
 
         If *debug* is True, print the commands executed.
-
-        Implemented by subclasses.
         """
 
-        raise NotImplementedError
-
+    @abstractmethod
     def with_optimization_level(self, level, **extra):
         """Return a new Toolchain object with the optimization level
         set to `level` , on the scale defined by the gcc -O option.
@@ -133,16 +132,36 @@ def with_optimization_level(self, level, **extra):
         simply ignore it.
 
         Level may also be "debug" to specify a debug build.
-
-        Implemented by subclasses.
         """
 
-        raise NotImplementedError
-
 
 # {{{ gcc-like tool chain
 
+@dataclass(frozen=True)
 class GCCLikeToolchain(Toolchain):
+    #: Path to the C compiler.
+    cc: str
+    #: Path to linker.
+    ld: str
+
+    #: A list of flags to pass to the C compiler.
+    cflags: List[str]
+    #: A list of linker flags.
+    ldflags: List[str]
+
+    #: A list of defines to pass to the C compiler.
+    defines: List[str]
+    # A list of variables to undefine.
+    undefines: List[str]
+
+    #: Extension for shared library generated by the compiler.
+    so_ext: str
+    #: Extension of the object file generated by the compiler.
+    o_ext: str
+
+    def _cmdline(self, source_files, object=False):
+        raise NotImplementedError
+
     def get_version(self):
         result, stdout, stderr = call_capture_output([self.cc, "--version"])
         if result != 0:
@@ -233,6 +252,7 @@ def link_extension(self, ext_file, object_files, debug=False):
 
 # {{{ gcc toolchain
 
+@dataclass(frozen=True)
 class GCCToolchain(GCCLikeToolchain):
     def get_version_tuple(self):
         ver = self.get_version()
@@ -288,13 +308,14 @@ def remove_prefix(flags, prefix):
             if level >= 2 and self.get_version_tuple() >= (4, 3):
                 oflags.extend(["-march=native", "-mtune=native", ])
 
-        return self.copy(cflags=cflags + oflags)
+        return replace(self, cflags=cflags + oflags)
 
 # }}}
 
 
 # {{{ nvcc
 
+@dataclass(frozen=True)
 class NVCCToolchain(GCCLikeToolchain):
     def get_version_tuple(self):
         ver = self.get_version()
@@ -358,6 +379,9 @@ def build_object(self, ext_file, source_files, debug=False):
                   file=sys.stderr)
             raise CompileError("module compilation failed")
 
+    def with_optimization_level(self, level, **extra):
+        raise NotImplementedError
+
 # }}}
 
 
@@ -412,13 +436,15 @@ def _guess_toolchain_kwargs_from_python_config():
             "o_ext": object_suffix,
             "defines": defines,
             "undefines": undefines,
+            "features": set(),
             }
 
 
 def call_capture_output(*args):
-    from pytools.prefork import call_capture_output
     import sys
 
+    from pytools.prefork import call_capture_output
+
     encoding = sys.getdefaultencoding()
     result, stdout, stderr = call_capture_output(*args)
     return result, stdout.decode(encoding), stderr.decode(encoding)
@@ -446,7 +472,20 @@ def guess_toolchain():
             if sys.maxsize == 0x7fffffff:
                 kwargs["cflags"].extend(["-arch", "i386"])
 
-        return GCCToolchain(**kwargs)
+        return GCCToolchain(
+            cc=kwargs["cc"],
+            ld=kwargs["ld"],
+            library_dirs=kwargs["library_dirs"],
+            libraries=kwargs["libraries"],
+            include_dirs=kwargs["include_dirs"],
+            cflags=kwargs["cflags"],
+            ldflags=kwargs["ldflags"],
+            defines=kwargs["defines"],
+            undefines=kwargs["undefines"],
+            so_ext=kwargs["so_ext"],
+            o_ext=kwargs["o_ext"],
+            features=set(),
+            )
     else:
         raise ToolchainGuessError(
                 "Unable to determine compiler. Tried running "
@@ -469,7 +508,6 @@ def guess_nvcc_toolchain():
             "undefines": gcc_kwargs["undefines"],
             }
     kwargs.setdefault("undefines", []).append("__BLOCKS__")
-    kwargs["cc"] = "nvcc"
 
     return NVCCToolchain(**kwargs)
 
diff --git a/examples/demo.py b/examples/demo.py
index 966c7eb..0923b4a 100644
--- a/examples/demo.py
+++ b/examples/demo.py
@@ -1,5 +1,8 @@
 import cgen as c
+
 from codepy.bpl import BoostPythonModule
+
+
 mod = BoostPythonModule()
 
 mod.add_function(
@@ -9,6 +12,8 @@
             ))
 
 from codepy.toolchain import guess_toolchain
+
+
 cmod = mod.compile(guess_toolchain())
 
 print(cmod.greet())
diff --git a/examples/demo_plain.py b/examples/demo_plain.py
index babde52..80f0ce1 100644
--- a/examples/demo_plain.py
+++ b/examples/demo_plain.py
@@ -16,12 +16,18 @@
 """
 
 from codepy.toolchain import guess_toolchain
+
+
 toolchain = guess_toolchain()
 
 from codepy.libraries import add_boost_python
+
+
 add_boost_python(toolchain)
 
 from codepy.jit import extension_from_string
+
+
 cmod = extension_from_string(toolchain, "module", MODULE_CODE)
 
 print(cmod.greet())
diff --git a/examples/nvcc-test.py b/examples/nvcc-test.py
index 28e6bfa..1ebf7d1 100644
--- a/examples/nvcc-test.py
+++ b/examples/nvcc-test.py
@@ -1,7 +1,9 @@
 import cgen as c
+from cgen.cuda import CudaGlobal
+
 from codepy.bpl import BoostPythonModule
 from codepy.cuda import CudaModule
-from cgen.cuda import CudaGlobal
+
 
 # This file tests the ability to use compile and link CUDA code into the
 # Python interpreter.  Running this test requires PyCUDA
@@ -11,9 +13,11 @@
 # The host module should include a function which is callable from Python
 host_mod = BoostPythonModule()
 
+import math
 # Are we on a 32 or 64 bit platform?
 import sys
-import math
+
+
 bitness = math.log(sys.maxsize) + 1
 ptr_sz_uint_conv = "K" if bitness > 32 else "I"
 
@@ -99,16 +103,17 @@
 import codepy.jit
 import codepy.toolchain
 
+
 gcc_toolchain = codepy.toolchain.guess_toolchain()
 nvcc_toolchain = codepy.toolchain.guess_nvcc_toolchain()
 
 module = cuda_mod.compile(gcc_toolchain, nvcc_toolchain, debug=True)
+import numpy as np
 import pycuda.autoinit
 import pycuda.driver
+import pycuda.gpuarray
 
 
-import pycuda.gpuarray
-import numpy as np
 length = 25
 constant_value = 2
 # This is a strange way to create a GPUArray, but is meant to illustrate
diff --git a/setup.cfg b/setup.cfg
index a1a0478..6b47f35 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -7,3 +7,12 @@ docstring-quotes = """
 multiline-quotes = """
 
 # enable-flake8-bugbear
+# enable-flake8-isort
+
+[isort]
+known_firstparty=pytools
+known_local_folder=codepy
+line_length = 85
+lines_after_imports = 2
+combine_as_imports = True
+multi_line_output = 4
diff --git a/setup.py b/setup.py
index f78ef4d..6da6b6f 100644
--- a/setup.py
+++ b/setup.py
@@ -1,6 +1,7 @@
 #!/usr/bin/env python
 
-from setuptools import setup, find_packages
+from setuptools import find_packages, setup
+
 
 setup(
     name="codepy",
diff --git a/test/test_identical_symbols.py b/test/test_identical_symbols.py
index 20de29f..98f1678 100644
--- a/test/test_identical_symbols.py
+++ b/test/test_identical_symbols.py
@@ -2,8 +2,9 @@
 
 
 def make_greet_mod(greeting):
-    from cgen import FunctionBody, FunctionDeclaration, Block, \
-            Const, Pointer, Value, Statement
+    from cgen import (
+        Block, Const, FunctionBody, FunctionDeclaration, Pointer, Statement, Value)
+
     from codepy.bpl import BoostPythonModule
 
     mod = BoostPythonModule()
diff --git a/test/test_two_stage_compile.py b/test/test_two_stage_compile.py
index 2500894..0a18e41 100644
--- a/test/test_two_stage_compile.py
+++ b/test/test_two_stage_compile.py
@@ -1,7 +1,8 @@
-from codepy.toolchain import guess_toolchain
-from codepy.jit import compile_from_string
 from ctypes import CDLL
 
+from codepy.jit import compile_from_string
+from codepy.toolchain import guess_toolchain
+
 
 def test():
     toolchain = guess_toolchain()