diff --git a/netlib/certutils.py b/netlib/certutils.py
index a0111381c..616a778e4 100644
--- a/netlib/certutils.py
+++ b/netlib/certutils.py
@@ -12,7 +12,10 @@ from pyasn1.codec.der.decoder import decode
 from pyasn1.error import PyAsn1Error
 import OpenSSL
 
+from .utils import Serializable
+
 # Default expiry must not be too long: https://github.com/mitmproxy/mitmproxy/issues/815
+
 DEFAULT_EXP = 94608000  # = 24 * 60 * 60 * 365 * 3
 # Generated with "openssl dhparam". It's too slow to generate this on startup.
 DEFAULT_DHPARAM = b"""
@@ -361,7 +364,7 @@ class _GeneralNames(univ.SequenceOf):
         constraint.ValueSizeConstraint(1, 1024)
 
 
-class SSLCert(object):
+class SSLCert(Serializable):
 
     def __init__(self, cert):
         """
@@ -375,15 +378,25 @@ class SSLCert(object):
     def __ne__(self, other):
         return not self.__eq__(other)
 
-    @classmethod
-    def from_pem(klass, txt):
-        x509 = OpenSSL.crypto.load_certificate(OpenSSL.crypto.FILETYPE_PEM, txt)
-        return klass(x509)
+    def get_state(self):
+        return self.to_pem()
+
+    def set_state(self, state):
+        self.x509 = OpenSSL.crypto.load_certificate(OpenSSL.crypto.FILETYPE_PEM, state)
 
     @classmethod
-    def from_der(klass, der):
+    def from_state(cls, state):
+        cls.from_pem(state)
+
+    @classmethod
+    def from_pem(cls, txt):
+        x509 = OpenSSL.crypto.load_certificate(OpenSSL.crypto.FILETYPE_PEM, txt)
+        return cls(x509)
+
+    @classmethod
+    def from_der(cls, der):
         pem = ssl.DER_cert_to_PEM_cert(der)
-        return klass.from_pem(pem)
+        return cls.from_pem(pem)
 
     def to_pem(self):
         return OpenSSL.crypto.dump_certificate(
diff --git a/netlib/http/headers.py b/netlib/http/headers.py
index 6eb9db92d..784047964 100644
--- a/netlib/http/headers.py
+++ b/netlib/http/headers.py
@@ -14,7 +14,7 @@ except ImportError:  # pragma: nocover
 
 import six
 
-from netlib.utils import always_byte_args, always_bytes
+from netlib.utils import always_byte_args, always_bytes, Serializable
 
 if six.PY2:  # pragma: nocover
     _native = lambda x: x
@@ -27,7 +27,7 @@ else:
     _always_byte_args = always_byte_args("utf-8", "surrogateescape")
 
 
-class Headers(MutableMapping):
+class Headers(MutableMapping, Serializable):
     """
     Header class which allows both convenient access to individual headers as well as
     direct access to the underlying raw data. Provides a full dictionary interface.
@@ -193,11 +193,10 @@ class Headers(MutableMapping):
     def copy(self):
         return Headers(copy.copy(self.fields))
 
-    # Implement the StateObject protocol from mitmproxy
     def get_state(self):
         return tuple(tuple(field) for field in self.fields)
 
-    def load_state(self, state):
+    def set_state(self, state):
         self.fields = [list(field) for field in state]
 
     @classmethod
diff --git a/netlib/http/message.py b/netlib/http/message.py
index 28f55fa25..e3d8ce375 100644
--- a/netlib/http/message.py
+++ b/netlib/http/message.py
@@ -4,9 +4,9 @@ import warnings
 
 import six
 
+from .headers import Headers
 from .. import encoding, utils
 
-
 CONTENT_MISSING = 0
 
 if six.PY2:  # pragma: nocover
@@ -18,7 +18,7 @@ else:
     _always_bytes = lambda x: utils.always_bytes(x, "utf-8", "surrogateescape")
 
 
-class MessageData(object):
+class MessageData(utils.Serializable):
     def __eq__(self, other):
         if isinstance(other, MessageData):
             return self.__dict__ == other.__dict__
@@ -27,8 +27,24 @@ class MessageData(object):
     def __ne__(self, other):
         return not self.__eq__(other)
 
+    def set_state(self, state):
+        for k, v in state.items():
+            if k == "headers":
+                v = Headers.from_state(v)
+            setattr(self, k, v)
 
-class Message(object):
+    def get_state(self):
+        state = vars(self).copy()
+        state["headers"] = state["headers"].get_state()
+        return state
+
+    @classmethod
+    def from_state(cls, state):
+        state["headers"] = Headers.from_state(state["headers"])
+        return cls(**state)
+
+
+class Message(utils.Serializable):
     def __init__(self, data):
         self.data = data
 
@@ -40,6 +56,16 @@ class Message(object):
     def __ne__(self, other):
         return not self.__eq__(other)
 
+    def get_state(self):
+        return self.data.get_state()
+
+    def set_state(self, state):
+        self.data.set_state(state)
+
+    @classmethod
+    def from_state(cls, state):
+        return cls(**state)
+
     @property
     def headers(self):
         """
diff --git a/netlib/http/request.py b/netlib/http/request.py
index 6dabb1896..0e0f88cec 100644
--- a/netlib/http/request.py
+++ b/netlib/http/request.py
@@ -16,9 +16,8 @@ from .message import Message, _native, _always_bytes, MessageData
 class RequestData(MessageData):
     def __init__(self, first_line_format, method, scheme, host, port, path, http_version, headers=None, content=None,
                  timestamp_start=None, timestamp_end=None):
-        if not headers:
-            headers = Headers()
-        assert isinstance(headers, Headers)
+        if not isinstance(headers, Headers):
+            headers = Headers(headers)
 
         self.first_line_format = first_line_format
         self.method = method
diff --git a/netlib/http/response.py b/netlib/http/response.py
index 66e5ded60..8f4d62158 100644
--- a/netlib/http/response.py
+++ b/netlib/http/response.py
@@ -12,9 +12,8 @@ from ..odict import ODict
 class ResponseData(MessageData):
     def __init__(self, http_version, status_code, reason=None, headers=None, content=None,
                  timestamp_start=None, timestamp_end=None):
-        if not headers:
-            headers = Headers()
-        assert isinstance(headers, Headers)
+        if not isinstance(headers, Headers):
+            headers = Headers(headers)
 
         self.http_version = http_version
         self.status_code = status_code
diff --git a/netlib/odict.py b/netlib/odict.py
index 90317e5e8..1e6e381af 100644
--- a/netlib/odict.py
+++ b/netlib/odict.py
@@ -3,6 +3,8 @@ import re
 import copy
 import six
 
+from .utils import Serializable
+
 
 def safe_subn(pattern, repl, target, *args, **kwargs):
     """
@@ -13,7 +15,7 @@ def safe_subn(pattern, repl, target, *args, **kwargs):
     return re.subn(str(pattern), str(repl), target, *args, **kwargs)
 
 
-class ODict(object):
+class ODict(Serializable):
 
     """
         A dictionary-like object for managing ordered (key, value) data. Think
@@ -172,12 +174,12 @@ class ODict(object):
     def get_state(self):
         return [tuple(i) for i in self.lst]
 
-    def load_state(self, state):
+    def set_state(self, state):
         self.lst = [list(i) for i in state]
 
     @classmethod
-    def from_state(klass, state):
-        return klass([list(i) for i in state])
+    def from_state(cls, state):
+        return cls([list(i) for i in state])
 
 
 class ODictCaseless(ODict):
diff --git a/netlib/tcp.py b/netlib/tcp.py
index 85b4b0e2e..c8548aea2 100644
--- a/netlib/tcp.py
+++ b/netlib/tcp.py
@@ -16,7 +16,7 @@ import six
 import OpenSSL
 from OpenSSL import SSL
 
-from . import certutils, version_check
+from . import certutils, version_check, utils
 
 # This is a rather hackish way to make sure that
 # the latest version of pyOpenSSL is actually installed.
@@ -298,7 +298,7 @@ class Reader(_FileLike):
             raise NotImplementedError("Can only peek into (pyOpenSSL) sockets")
 
 
-class Address(object):
+class Address(utils.Serializable):
 
     """
         This class wraps an IPv4/IPv6 tuple to provide named attributes and
@@ -309,6 +309,20 @@ class Address(object):
         self.address = tuple(address)
         self.use_ipv6 = use_ipv6
 
+    def get_state(self):
+        return {
+            "address": self.address,
+            "use_ipv6": self.use_ipv6
+        }
+
+    def set_state(self, state):
+        self.address = state["address"]
+        self.use_ipv6 = state["use_ipv6"]
+
+    @classmethod
+    def from_state(cls, state):
+        return Address(**state)
+
     @classmethod
     def wrap(cls, t):
         if isinstance(t, cls):
diff --git a/netlib/utils.py b/netlib/utils.py
index 1c1b617ac..d2fc7195b 100644
--- a/netlib/utils.py
+++ b/netlib/utils.py
@@ -1,14 +1,45 @@
 from __future__ import absolute_import, print_function, division
 import os.path
 import re
-import string
 import codecs
 import unicodedata
+from abc import ABCMeta, abstractmethod
+
 import six
 
 from six.moves import urllib
 import hyperframe
 
+
+@six.add_metaclass(ABCMeta)
+class Serializable(object):
+    """
+    Abstract Base Class that defines an API to save an object's state and restore it later on.
+    """
+
+    @classmethod
+    @abstractmethod
+    def from_state(cls, state):
+        """
+        Create a new object from the given state.
+        """
+        raise NotImplementedError()
+
+    @abstractmethod
+    def get_state(self):
+        """
+        Retrieve object state.
+        """
+        raise NotImplementedError()
+
+    @abstractmethod
+    def set_state(self, state):
+        """
+        Set object state to the given state.
+        """
+        raise NotImplementedError()
+
+
 def always_bytes(unicode_or_bytes, *encode_args):
     if isinstance(unicode_or_bytes, six.text_type):
         return unicode_or_bytes.encode(*encode_args)
diff --git a/test/http/test_headers.py b/test/http/test_headers.py
index 8bddc0b2f..d50fee3e4 100644
--- a/test/http/test_headers.py
+++ b/test/http/test_headers.py
@@ -148,5 +148,5 @@ class TestHeaders(object):
 
         headers2 = Headers()
         assert headers != headers2
-        headers2.load_state(headers.get_state())
+        headers2.set_state(headers.get_state())
         assert headers == headers2
diff --git a/test/http/test_request.py b/test/http/test_request.py
index 8cf69ffe2..900b2cd1c 100644
--- a/test/http/test_request.py
+++ b/test/http/test_request.py
@@ -12,7 +12,7 @@ from .test_message import _test_decoded_attr, _test_passthrough_attr
 
 class TestRequestData(object):
     def test_init(self):
-        with raises(AssertionError):
+        with raises(ValueError if six.PY2 else TypeError):
             treq(headers="foobar")
 
         assert isinstance(treq(headers=None).headers, Headers)
diff --git a/test/http/test_response.py b/test/http/test_response.py
index a1f4abd72..145880000 100644
--- a/test/http/test_response.py
+++ b/test/http/test_response.py
@@ -1,5 +1,7 @@
 from __future__ import absolute_import, print_function, division
 
+import six
+
 from netlib.http import Headers
 from netlib.odict import ODict, ODictCaseless
 from netlib.tutils import raises, tresp
@@ -8,7 +10,7 @@ from .test_message import _test_passthrough_attr, _test_decoded_attr
 
 class TestResponseData(object):
     def test_init(self):
-        with raises(AssertionError):
+        with raises(ValueError if six.PY2 else TypeError):
             tresp(headers="foobar")
 
         assert isinstance(tresp(headers=None).headers, Headers)
diff --git a/test/test_odict.py b/test/test_odict.py
index 881970263..f0985ef64 100644
--- a/test/test_odict.py
+++ b/test/test_odict.py
@@ -24,7 +24,7 @@ class TestODict(object):
         nd = odict.ODict.from_state(state)
         assert nd == od
         b = odict.ODict()
-        b.load_state(state)
+        b.set_state(state)
         assert b == od
 
     def test_in_any(self):