diff --git a/examples/add_header.py b/examples/add_header.py
index 0c0593d1f..cf1b53cc8 100644
--- a/examples/add_header.py
+++ b/examples/add_header.py
@@ -1,2 +1,2 @@
 def response(context, flow):
-    flow.response.headers["newheader"] = ["foo"]
+    flow.response.headers["newheader"] = "foo"
diff --git a/examples/har_extractor.py b/examples/har_extractor.py
index f06efec39..bc784dc47 100644
--- a/examples/har_extractor.py
+++ b/examples/har_extractor.py
@@ -147,8 +147,8 @@ def response(context, flow):
     response_body_size = len(flow.response.content)
     response_body_decoded_size = len(flow.response.get_decoded_content())
     response_body_compression = response_body_decoded_size - response_body_size
-    response_mime_type = flow.response.headers.get_first('Content-Type', '')
-    response_redirect_url = flow.response.headers.get_first('Location', '')
+    response_mime_type = flow.response.headers.get('Content-Type', '')
+    response_redirect_url = flow.response.headers.get('Location', '')
 
     entry = HAR.entries(
         {
@@ -201,12 +201,12 @@ def response(context, flow):
     # Lookup the referer in the page_ref of context.HARLog to point this entries
     # pageref attribute to the right pages object, then set it as a new
     # reference to build a reference tree.
-    elif context.HARLog.get_page_ref(flow.request.headers.get('Referer', (None, ))[0]) is not None:
+    elif context.HARLog.get_page_ref(flow.request.headers.get('Referer')) is not None:
         entry['pageref'] = context.HARLog.get_page_ref(
-            flow.request.headers['Referer'][0]
+            flow.request.headers['Referer']
         )
         context.HARLog.set_page_ref(
-            flow.request.headers['Referer'][0], entry['pageref']
+            flow.request.headers['Referer'], entry['pageref']
         )
 
     context.HARLog.add(entry)
diff --git a/examples/modify_form.py b/examples/modify_form.py
index c2f0a47e5..3e9d15c00 100644
--- a/examples/modify_form.py
+++ b/examples/modify_form.py
@@ -1,5 +1,5 @@
 def request(context, flow):
-    if "application/x-www-form-urlencoded" in flow.request.headers["content-type"]:
+    if "application/x-www-form-urlencoded" in flow.request.headers.get("content-type", ""):
         form = flow.request.get_form_urlencoded()
         form["mitmproxy"] = ["rocks"]
         flow.request.set_form_urlencoded(form)
diff --git a/examples/redirect_requests.py b/examples/redirect_requests.py
index 2ae4927bf..ca24c42a8 100644
--- a/examples/redirect_requests.py
+++ b/examples/redirect_requests.py
@@ -2,8 +2,7 @@
 This example shows two ways to redirect flows to other destinations.
 """
 from libmproxy.models import HTTPResponse
-from netlib.odict import ODictCaseless
-
+from netlib.http import Headers
 
 def request(context, flow):
     # pretty_host(hostheader=True) takes the Host: header of the request into account,
@@ -14,7 +13,7 @@ def request(context, flow):
     if flow.request.pretty_host(hostheader=True).endswith("example.com"):
         resp = HTTPResponse(
             [1, 1], 200, "OK",
-            ODictCaseless([["Content-Type", "text/html"]]),
+            Headers(Content_Type="text/html"),
             "helloworld")
         flow.reply(resp)
 
diff --git a/examples/stickycookies b/examples/stickycookies
index 67b31da1d..7e84f71cd 100755
--- a/examples/stickycookies
+++ b/examples/stickycookies
@@ -23,16 +23,16 @@ class StickyMaster(controller.Master):
 
     def handle_request(self, flow):
         hid = (flow.request.host, flow.request.port)
-        if flow.request.headers["cookie"]:
-            self.stickyhosts[hid] = flow.request.headers["cookie"]
+        if "cookie" in flow.request.headers:
+            self.stickyhosts[hid] = flow.request.headers.get_all("cookie")
         elif hid in self.stickyhosts:
-            flow.request.headers["cookie"] = self.stickyhosts[hid]
+            flow.request.headers.set_all("cookie", self.stickyhosts[hid])
         flow.reply()
 
     def handle_response(self, flow):
         hid = (flow.request.host, flow.request.port)
-        if flow.response.headers["set-cookie"]:
-            self.stickyhosts[hid] = flow.response.headers["set-cookie"]
+        if "set-cookie" in flow.response.headers:
+            self.stickyhosts[hid] = flow.response.headers.get_all("set-cookie")
         flow.reply()
 
 
diff --git a/examples/upsidedownternet.py b/examples/upsidedownternet.py
index e8444c839..f2e730475 100644
--- a/examples/upsidedownternet.py
+++ b/examples/upsidedownternet.py
@@ -4,7 +4,7 @@ from libmproxy.models import decoded
 
 
 def response(context, flow):
-    if flow.response.headers.get_first("content-type", "").startswith("image"):
+    if flow.response.headers.get("content-type", "").startswith("image"):
         with decoded(flow.response):  # automatically decode gzipped responses.
             try:
                 s = cStringIO.StringIO(flow.response.content)
@@ -12,6 +12,6 @@ def response(context, flow):
                 s2 = cStringIO.StringIO()
                 img.save(s2, "png")
                 flow.response.content = s2.getvalue()
-                flow.response.headers["content-type"] = ["image/png"]
+                flow.response.headers["content-type"] = "image/png"
             except:  # Unknown image types etc.
                 pass
diff --git a/libmproxy/console/common.py b/libmproxy/console/common.py
index c25f7267f..ae3dd61ee 100644
--- a/libmproxy/console/common.py
+++ b/libmproxy/console/common.py
@@ -415,9 +415,9 @@ def format_flow(f, focus, extended=False, hostheader=False, padding=2,
             resp_clen = contentdesc,
             roundtrip = roundtrip,
         ))
-        t = f.response.headers["content-type"]
+        t = f.response.headers.get("content-type")
         if t:
-            d["resp_ctype"] = t[0].split(";")[0]
+            d["resp_ctype"] = t.split(";")[0]
         else:
             d["resp_ctype"] = ""
     return flowcache.get(
diff --git a/libmproxy/console/contentview.py b/libmproxy/console/contentview.py
index 95ea7b172..17ed90e1d 100644
--- a/libmproxy/console/contentview.py
+++ b/libmproxy/console/contentview.py
@@ -12,7 +12,7 @@ import urwid
 import html2text
 
 import netlib.utils
-from netlib import odict, encoding
+from netlib import encoding
 
 from . import common, signals
 from .. import utils
@@ -74,7 +74,7 @@ class ViewAuto:
     content_types = []
 
     def __call__(self, hdrs, content, limit):
-        ctype = hdrs.get_first("content-type")
+        ctype = hdrs.get("content-type")
         if ctype:
             ct = netlib.utils.parse_content_type(ctype) if ctype else None
             ct = "%s/%s" % (ct[0], ct[1])
@@ -508,7 +508,7 @@ def get(name):
             return i
 
 
-def get_content_view(viewmode, hdrItems, content, limit, is_request):
+def get_content_view(viewmode, headers, content, limit, is_request):
     """
         Returns a (msg, body) tuple.
     """
@@ -519,16 +519,14 @@ def get_content_view(viewmode, hdrItems, content, limit, is_request):
             return "No content", ""
     msg = []
 
-    hdrs = odict.ODictCaseless([list(i) for i in hdrItems])
-
-    enc = hdrs.get_first("content-encoding")
+    enc = headers.get("content-encoding")
     if enc and enc != "identity":
         decoded = encoding.decode(enc, content)
         if decoded:
             content = decoded
             msg.append("[decoded %s]" % enc)
     try:
-        ret = viewmode(hdrs, content, limit)
+        ret = viewmode(headers, content, limit)
     # Third-party viewers can fail in unexpected ways...
     except Exception:
         s = traceback.format_exc()
@@ -536,7 +534,7 @@ def get_content_view(viewmode, hdrItems, content, limit, is_request):
         signals.add_event(s, "error")
         ret = None
     if not ret:
-        ret = get("Raw")(hdrs, content, limit)
+        ret = get("Raw")(headers, content, limit)
         msg.append("Couldn't parse: falling back to Raw")
     else:
         msg.append(ret[0])
diff --git a/libmproxy/console/flowview.py b/libmproxy/console/flowview.py
index 8b8286531..19917555a 100644
--- a/libmproxy/console/flowview.py
+++ b/libmproxy/console/flowview.py
@@ -4,7 +4,7 @@ import sys
 import urwid
 
 from netlib import odict
-from netlib.http.semantics import CONTENT_MISSING
+from netlib.http.semantics import CONTENT_MISSING, Headers
 
 from . import common, grideditor, contentview, signals, searchable, tabs
 from . import flowdetailview
@@ -182,7 +182,7 @@ class FlowView(tabs.Tabs):
             description, text_objects = cache.get(
                 contentview.get_content_view,
                 viewmode,
-                tuple(tuple(i) for i in conn.headers.lst),
+                conn.headers,
                 conn.content,
                 limit,
                 isinstance(conn, HTTPRequest)
@@ -199,7 +199,7 @@ class FlowView(tabs.Tabs):
     def conn_text(self, conn):
         if conn:
             txt = common.format_keyvals(
-                [(h + ":", v) for (h, v) in conn.headers.lst],
+                [(h + ":", v) for (h, v) in conn.headers.fields],
                 key = "header",
                 val = "text"
             )
@@ -284,8 +284,8 @@ class FlowView(tabs.Tabs):
         response.msg = msg
         signals.flow_change.send(self, flow = self.flow)
 
-    def set_headers(self, lst, conn):
-        conn.headers = odict.ODictCaseless(lst)
+    def set_headers(self, fields, conn):
+        conn.headers = Headers(fields)
         signals.flow_change.send(self, flow = self.flow)
 
     def set_query(self, lst, conn):
@@ -330,7 +330,7 @@ class FlowView(tabs.Tabs):
             if not self.flow.response:
                 self.flow.response = HTTPResponse(
                     self.flow.request.httpversion,
-                    200, "OK", odict.ODictCaseless(), ""
+                    200, "OK", Headers(), ""
                 )
                 self.flow.response.reply = controller.DummyReply()
             message = self.flow.response
@@ -381,7 +381,7 @@ class FlowView(tabs.Tabs):
             self.master.view_grideditor(
                 grideditor.HeaderEditor(
                     self.master,
-                    message.headers.lst,
+                    message.headers.fields,
                     self.set_headers,
                     message
                 )
@@ -616,8 +616,7 @@ class FlowView(tabs.Tabs):
                 key = None
             elif key == "v":
                 if conn.content:
-                    t = conn.headers["content-type"] or [None]
-                    t = t[0]
+                    t = conn.headers.get("content-type")
                     if "EDITOR" in os.environ or "PAGER" in os.environ:
                         self.master.spawn_external_viewer(conn.content, t)
                     else:
@@ -626,7 +625,7 @@ class FlowView(tabs.Tabs):
                         )
             elif key == "z":
                 self.flow.backup()
-                e = conn.headers.get_first("content-encoding", "identity")
+                e = conn.headers.get("content-encoding", "identity")
                 if e != "identity":
                     if not conn.decode():
                         signals.status_message.send(
diff --git a/libmproxy/dump.py b/libmproxy/dump.py
index bf4098035..17b47dd2b 100644
--- a/libmproxy/dump.py
+++ b/libmproxy/dump.py
@@ -174,7 +174,7 @@ class DumpMaster(flow.FlowMaster):
 
     def _print_message(self, message):
         if self.o.flow_detail >= 2:
-            print(self.indent(4, message.headers.format()), file=self.outfile)
+            print(self.indent(4, str(message.headers)), file=self.outfile)
         if self.o.flow_detail >= 3:
             if message.content == CONTENT_MISSING:
                 print(self.indent(4, "(content missing)"), file=self.outfile)
diff --git a/libmproxy/filt.py b/libmproxy/filt.py
index 6abc4a11b..7cd0f4dfb 100644
--- a/libmproxy/filt.py
+++ b/libmproxy/filt.py
@@ -77,17 +77,19 @@ class FResp(_Action):
 
 
 class _Rex(_Action):
+    flags = 0
+
     def __init__(self, expr):
         self.expr = expr
         try:
-            self.re = re.compile(self.expr)
+            self.re = re.compile(self.expr, self.flags)
         except:
             raise ValueError("Cannot compile expression.")
 
 
 def _check_content_type(expr, o):
-    val = o.headers["content-type"]
-    if val and re.search(expr, val[0]):
+    val = o.headers.get("content-type")
+    if val and re.search(expr, val):
         return True
     return False
 
@@ -145,11 +147,12 @@ class FResponseContentType(_Rex):
 class FHead(_Rex):
     code = "h"
     help = "Header"
+    flags = re.MULTILINE
 
     def __call__(self, f):
-        if f.request.headers.match_re(self.expr):
+        if f.request and self.re.search(str(f.request.headers)):
             return True
-        elif f.response and f.response.headers.match_re(self.expr):
+        if f.response and self.re.search(str(f.response.headers)):
             return True
         return False
 
@@ -157,18 +160,20 @@ class FHead(_Rex):
 class FHeadRequest(_Rex):
     code = "hq"
     help = "Request header"
+    flags = re.MULTILINE
 
     def __call__(self, f):
-        if f.request.headers.match_re(self.expr):
+        if f.request and self.re.search(str(f.request.headers)):
             return True
 
 
 class FHeadResponse(_Rex):
     code = "hs"
     help = "Response header"
+    flags = re.MULTILINE
 
     def __call__(self, f):
-        if f.response and f.response.headers.match_re(self.expr):
+        if f.response and self.re.search(str(f.response.headers)):
             return True
 
 
@@ -178,10 +183,10 @@ class FBod(_Rex):
 
     def __call__(self, f):
         if f.request and f.request.content:
-            if re.search(self.expr, f.request.get_decoded_content()):
+            if self.re.search(f.request.get_decoded_content()):
                 return True
         if f.response and f.response.content:
-            if re.search(self.expr, f.response.get_decoded_content()):
+            if self.re.search(f.response.get_decoded_content()):
                 return True
         return False
 
@@ -192,7 +197,7 @@ class FBodRequest(_Rex):
 
     def __call__(self, f):
         if f.request and f.request.content:
-            if re.search(self.expr, f.request.get_decoded_content()):
+            if self.re.search(f.request.get_decoded_content()):
                 return True
 
 
@@ -202,24 +207,26 @@ class FBodResponse(_Rex):
 
     def __call__(self, f):
         if f.response and f.response.content:
-            if re.search(self.expr, f.response.get_decoded_content()):
+            if self.re.search(f.response.get_decoded_content()):
                 return True
 
 
 class FMethod(_Rex):
     code = "m"
     help = "Method"
+    flags = re.IGNORECASE
 
     def __call__(self, f):
-        return bool(re.search(self.expr, f.request.method, re.IGNORECASE))
+        return bool(self.re.search(f.request.method))
 
 
 class FDomain(_Rex):
     code = "d"
     help = "Domain"
+    flags = re.IGNORECASE
 
     def __call__(self, f):
-        return bool(re.search(self.expr, f.request.host, re.IGNORECASE))
+        return bool(self.re.search(f.request.host))
 
 
 class FUrl(_Rex):
@@ -234,21 +241,24 @@ class FUrl(_Rex):
         return klass(*toks)
 
     def __call__(self, f):
-        return re.search(self.expr, f.request.url)
+        return self.re.search(f.request.url)
+
 
 class FSrc(_Rex):
     code = "src"
     help = "Match source address"
 
     def __call__(self, f):
-        return f.client_conn.address and re.search(self.expr, repr(f.client_conn.address))
+        return f.client_conn.address and self.re.search(repr(f.client_conn.address))
+
 
 class FDst(_Rex):
     code = "dst"
     help = "Match destination address"
 
     def __call__(self, f):
-        return f.server_conn.address and re.search(self.expr, repr(f.server_conn.address))
+        return f.server_conn.address and self.re.search(repr(f.server_conn.address))
+
 
 class _Int(_Action):
     def __init__(self, num):
diff --git a/libmproxy/flow.py b/libmproxy/flow.py
index 5eac8da92..547d0f604 100644
--- a/libmproxy/flow.py
+++ b/libmproxy/flow.py
@@ -11,8 +11,8 @@ import re
 import urlparse
 
 
-from netlib import odict, wsgi
-from netlib.http.semantics import CONTENT_MISSING
+from netlib import wsgi
+from netlib.http.semantics import CONTENT_MISSING, Headers
 import netlib.http
 from . import controller, tnetstring, filt, script, version
 from .onboarding import app
@@ -45,7 +45,7 @@ class AppRegistry:
         if (request.host, request.port) in self.apps:
             return self.apps[(request.host, request.port)]
         if "host" in request.headers:
-            host = request.headers["host"][0]
+            host = request.headers["host"]
             return self.apps.get((host, request.port), None)
 
 
@@ -144,15 +144,15 @@ class SetHeaders:
         for _, header, value, cpatt in self.lst:
             if cpatt(f):
                 if f.response:
-                    del f.response.headers[header]
+                    f.response.headers.pop(header, None)
                 else:
-                    del f.request.headers[header]
+                    f.request.headers.pop(header, None)
         for _, header, value, cpatt in self.lst:
             if cpatt(f):
                 if f.response:
-                    f.response.headers.add(header, value)
+                    f.response.headers.fields.append((header, value))
                 else:
-                    f.request.headers.add(header, value)
+                    f.request.headers.fields.append((header, value))
 
 
 class StreamLargeBodies(object):
@@ -278,14 +278,11 @@ class ServerPlaybackState:
             key.append(p[1])
 
         if self.headers:
-            hdrs = []
+            headers = []
             for i in self.headers:
-                v = r.headers[i]
-                # Slightly subtle: we need to convert everything to strings
-                # to prevent a mismatch between unicode/non-unicode.
-                v = [str(x) for x in v]
-                hdrs.append((i, v))
-            key.append(hdrs)
+                v = r.headers.get(i)
+                headers.append((i, v))
+            key.append(headers)
         return hashlib.sha256(repr(key)).digest()
 
     def next_flow(self, request):
@@ -329,7 +326,7 @@ class StickyCookieState:
         return False
 
     def handle_response(self, f):
-        for i in f.response.headers["set-cookie"]:
+        for i in f.response.headers.get_all("set-cookie"):
             # FIXME: We now know that Cookie.py screws up some cookies with
             # valid RFC 822/1123 datetime specifications for expiry. Sigh.
             c = Cookie.SimpleCookie(str(i))
@@ -351,7 +348,7 @@ class StickyCookieState:
                     l.append(self.jar[i].output(header="").strip())
         if l:
             f.request.stickycookie = True
-            f.request.headers["cookie"] = l
+            f.request.headers.set_all("cookie",l)
 
 
 class StickyAuthState:
@@ -836,7 +833,7 @@ class FlowMaster(controller.Master):
             ssl_established=True
         ))
         f = HTTPFlow(c, s)
-        headers = odict.ODictCaseless()
+        headers = Headers()
 
         req = HTTPRequest(
             "absolute",
@@ -930,8 +927,7 @@ class FlowMaster(controller.Master):
             f.backup()
             f.request.is_replay = True
             if f.request.content:
-                f.request.headers[
-                    "Content-Length"] = [str(len(f.request.content))]
+                f.request.headers["Content-Length"] = str(len(f.request.content))
             f.response = None
             f.error = None
             self.process_new_request(f)
diff --git a/libmproxy/models/http.py b/libmproxy/models/http.py
index fb2f305bb..0d5e53b59 100644
--- a/libmproxy/models/http.py
+++ b/libmproxy/models/http.py
@@ -5,8 +5,8 @@ from email.utils import parsedate_tz, formatdate, mktime_tz
 import time
 
 from libmproxy import utils
-from netlib import odict, encoding
-from netlib.http import status_codes
+from netlib import encoding
+from netlib.http import status_codes, Headers
 from netlib.tcp import Address
 from netlib.http.semantics import Request, Response, CONTENT_MISSING
 from .. import version, stateobject
@@ -16,7 +16,7 @@ from .flow import Flow
 class MessageMixin(stateobject.StateObject):
     _stateobject_attributes = dict(
         httpversion=tuple,
-        headers=odict.ODictCaseless,
+        headers=Headers,
         body=str,
         timestamp_start=float,
         timestamp_end=float
@@ -40,7 +40,7 @@ class MessageMixin(stateobject.StateObject):
             header.
             Doesn't change the message iteself or its headers.
         """
-        ce = self.headers.get_first("content-encoding")
+        ce = self.headers.get("content-encoding")
         if not self.body or ce not in encoding.ENCODINGS:
             return self.body
         return encoding.decode(ce, self.body)
@@ -53,14 +53,14 @@ class MessageMixin(stateobject.StateObject):
 
             Returns True if decoding succeeded, False otherwise.
         """
-        ce = self.headers.get_first("content-encoding")
+        ce = self.headers.get("content-encoding")
         if not self.body or ce not in encoding.ENCODINGS:
             return False
         data = encoding.decode(ce, self.body)
         if data is None:
             return False
         self.body = data
-        del self.headers["content-encoding"]
+        self.headers.pop("content-encoding", None)
         return True
 
     def encode(self, e):
@@ -70,7 +70,7 @@ class MessageMixin(stateobject.StateObject):
         """
         # FIXME: Error if there's an existing encoding header?
         self.body = encoding.encode(e, self.body)
-        self.headers["content-encoding"] = [e]
+        self.headers["content-encoding"] = e
 
     def copy(self):
         c = copy.copy(self)
@@ -86,11 +86,18 @@ class MessageMixin(stateobject.StateObject):
             Returns the number of replacements made.
         """
         with decoded(self):
-            self.body, c = utils.safe_subn(
+            self.body, count = utils.safe_subn(
                 pattern, repl, self.body, *args, **kwargs
             )
-        c += self.headers.replace(pattern, repl, *args, **kwargs)
-        return c
+        fields = []
+        for name, value in self.headers.fields:
+            name, c = utils.safe_subn(pattern, repl, name, *args, **kwargs)
+            count += c
+            value, c = utils.safe_subn(pattern, repl, value, *args, **kwargs)
+            count += c
+            fields.append([name, value])
+        self.headers.fields = fields
+        return count
 
 
 class HTTPRequest(MessageMixin, Request):
@@ -115,7 +122,7 @@ class HTTPRequest(MessageMixin, Request):
 
         httpversion: HTTP version tuple, e.g. (1,1)
 
-        headers: odict.ODictCaseless object
+        headers: Headers object
 
         content: Content of the request, None, or CONTENT_MISSING if there
         is content associated, but not present. CONTENT_MISSING evaluates
@@ -266,7 +273,7 @@ class HTTPResponse(MessageMixin, Response):
 
         msg: HTTP response message
 
-        headers: ODict Caseless object
+        headers: Headers object
 
         content: Content of the request, None, or CONTENT_MISSING if there
         is content associated, but not present. CONTENT_MISSING evaluates
@@ -379,15 +386,15 @@ class HTTPResponse(MessageMixin, Response):
         ]
         for i in refresh_headers:
             if i in self.headers:
-                d = parsedate_tz(self.headers[i][0])
+                d = parsedate_tz(self.headers[i])
                 if d:
                     new = mktime_tz(d) + delta
-                    self.headers[i] = [formatdate(new)]
+                    self.headers[i] = formatdate(new)
         c = []
-        for i in self.headers["set-cookie"]:
+        for i in self.headers.get_all("set-cookie"):
             c.append(self._refresh_cookie(i, delta))
         if c:
-            self.headers["set-cookie"] = c
+            self.headers.set_all("set-cookie", c)
 
 
 class HTTPFlow(Flow):
@@ -490,7 +497,7 @@ class decoded(object):
 
     def __init__(self, o):
         self.o = o
-        ce = o.headers.get_first("content-encoding")
+        ce = o.headers.get("content-encoding")
         if ce in encoding.ENCODINGS:
             self.ce = ce
         else:
@@ -517,11 +524,12 @@ def make_error_response(status_code, message, headers=None):
     """.strip() % (status_code, response, message)
 
     if not headers:
-        headers = odict.ODictCaseless()
-    headers["Server"] = [version.NAMEVERSION]
-    headers["Connection"] = ["close"]
-    headers["Content-Length"] = [len(body)]
-    headers["Content-Type"] = ["text/html"]
+        headers = Headers(
+            Server=version.NAMEVERSION,
+            Connection="close",
+            Content_Length=str(len(body)),
+            Content_Type="text/html"
+        )
 
     return HTTPResponse(
         (1, 1),  # FIXME: Should be a string.
@@ -536,15 +544,15 @@ def make_connect_request(address):
     address = Address.wrap(address)
     return HTTPRequest(
         "authority", "CONNECT", None, address.host, address.port, None, (1, 1),
-        odict.ODictCaseless(), ""
+        Headers(), ""
     )
 
 
 def make_connect_response(httpversion):
-    headers = odict.ODictCaseless([
-        ["Content-Length", "0"],
-        ["Proxy-Agent", version.NAMEVERSION]
-    ])
+    headers = Headers(
+        Content_Length="0",
+        Proxy_Agent=version.NAMEVERSION
+    )
     return HTTPResponse(
         httpversion,
         200,
diff --git a/libmproxy/protocol/http.py b/libmproxy/protocol/http.py
index f51fea957..fbf4ac9bf 100644
--- a/libmproxy/protocol/http.py
+++ b/libmproxy/protocol/http.py
@@ -1,7 +1,7 @@
 from __future__ import (absolute_import, print_function, division)
 
 from netlib import tcp
-from netlib.http import http1, HttpErrorConnClosed, HttpError
+from netlib.http import http1, HttpErrorConnClosed, HttpError, Headers
 from netlib.http.semantics import CONTENT_MISSING
 from netlib import odict
 from netlib.tcp import NetLibError, Address
@@ -568,10 +568,6 @@ class HttpLayer(Layer):
                 self.send_response(make_error_response(
                     407,
                     "Proxy Authentication Required",
-                    odict.ODictCaseless(
-                        [
-                            [k, v] for k, v in
-                            self.config.authenticator.auth_challenge_headers().items()
-                            ])
+                    Headers(**self.config.authenticator.auth_challenge_headers())
                 ))
                 raise InvalidCredentials("Proxy Authentication Required")
diff --git a/libmproxy/web/app.py b/libmproxy/web/app.py
index d6082ee24..2517e7ad2 100644
--- a/libmproxy/web/app.py
+++ b/libmproxy/web/app.py
@@ -27,8 +27,7 @@ class RequestHandler(tornado.web.RequestHandler):
 
     @property
     def json(self):
-        if not self.request.headers.get(
-                "Content-Type").startswith("application/json"):
+        if not self.request.headers.get("Content-Type").startswith("application/json"):
             return None
         return json.loads(self.request.body)
 
@@ -186,12 +185,12 @@ class FlowContent(RequestHandler):
         if not message.content:
             raise APIError(400, "No content.")
 
-        content_encoding = message.headers.get_first("Content-Encoding", None)
+        content_encoding = message.headers.get("Content-Encoding", None)
         if content_encoding:
             content_encoding = re.sub(r"[^\w]", "", content_encoding)
             self.set_header("Content-Encoding", content_encoding)
 
-        original_cd = message.headers.get_first("Content-Disposition", None)
+        original_cd = message.headers.get("Content-Disposition", None)
         filename = None
         if original_cd:
             filename = re.search("filename=([\w\" \.\-\(\)]+)", original_cd)
diff --git a/test/test_console_contentview.py b/test/test_console_contentview.py
index d1a6180fb..7e5a188fa 100644
--- a/test/test_console_contentview.py
+++ b/test/test_console_contentview.py
@@ -1,11 +1,13 @@
 import os
 from nose.plugins.skip import SkipTest
+from netlib.http import Headers
+
 if os.name == "nt":
     raise SkipTest("Skipped on Windows.")
 import sys
 
 import netlib.utils
-from netlib import odict, encoding
+from netlib import encoding
 
 import libmproxy.console.contentview as cv
 from libmproxy import utils, flow
@@ -33,34 +35,28 @@ class TestContentView:
     def test_view_auto(self):
         v = cv.ViewAuto()
         f = v(
-            odict.ODictCaseless(),
+            Headers(),
             "foo",
             1000
         )
         assert f[0] == "Raw"
 
         f = v(
-            odict.ODictCaseless(
-                [["content-type", "text/html"]],
-            ),
+            Headers(content_type="text/html"),
             "<html></html>",
             1000
         )
         assert f[0] == "HTML"
 
         f = v(
-            odict.ODictCaseless(
-                [["content-type", "text/flibble"]],
-            ),
+            Headers(content_type="text/flibble"),
             "foo",
             1000
         )
         assert f[0] == "Raw"
 
         f = v(
-            odict.ODictCaseless(
-                [["content-type", "text/flibble"]],
-            ),
+            Headers(content_type="text/flibble"),
             "<xml></xml>",
             1000
         )
@@ -168,28 +164,22 @@ Content-Disposition: form-data; name="submit-name"
 Larry
 --AaB03x
         """.strip()
-        h = odict.ODictCaseless(
-            [("Content-Type", "multipart/form-data; boundary=AaB03x")]
-        )
+        h = Headers(content_type="multipart/form-data; boundary=AaB03x"),
         assert view(h, v, 1000)
 
-        h = odict.ODictCaseless()
+        h = Headers(),
         assert not view(h, v, 1000)
 
-        h = odict.ODictCaseless(
-            [("Content-Type", "multipart/form-data")]
-        )
+        h = Headers(content_type="multipart/form-data"),
         assert not view(h, v, 1000)
 
-        h = odict.ODictCaseless(
-            [("Content-Type", "unparseable")]
-        )
+        h = Headers(content_type="unparseable"),
         assert not view(h, v, 1000)
 
     def test_get_content_view(self):
         r = cv.get_content_view(
             cv.get("Raw"),
-            [["content-type", "application/json"]],
+            Headers(content_type="application/json"),
             "[1, 2, 3]",
             1000,
             False
@@ -198,7 +188,7 @@ Larry
 
         r = cv.get_content_view(
             cv.get("Auto"),
-            [["content-type", "application/json"]],
+            Headers(content_type="application/json"),
             "[1, 2, 3]",
             1000,
             False
@@ -207,7 +197,7 @@ Larry
 
         r = cv.get_content_view(
             cv.get("Auto"),
-            [["content-type", "application/json"]],
+            Headers(content_type="application/json"),
             "[1, 2",
             1000,
             False
@@ -216,7 +206,7 @@ Larry
 
         r = cv.get_content_view(
             cv.get("AMF"),
-            [],
+            Headers(),
             "[1, 2",
             1000,
             False
@@ -225,10 +215,10 @@ Larry
 
         r = cv.get_content_view(
             cv.get("Auto"),
-            [
-                ["content-type", "application/json"],
-                ["content-encoding", "gzip"]
-            ],
+            Headers(
+                content_type="application/json",
+                content_encoding="gzip"
+            ),
             encoding.encode('gzip', "[1, 2, 3]"),
             1000,
             False
@@ -238,10 +228,10 @@ Larry
 
         r = cv.get_content_view(
             cv.get("XML"),
-            [
-                ["content-type", "application/json"],
-                ["content-encoding", "gzip"]
-            ],
+            Headers(
+                content_type="application/json",
+                content_encoding="gzip"
+            ),
             encoding.encode('gzip', "[1, 2, 3]"),
             1000,
             False
diff --git a/test/test_dump.py b/test/test_dump.py
index 9f055bac1..c76f555f2 100644
--- a/test/test_dump.py
+++ b/test/test_dump.py
@@ -145,7 +145,7 @@ class TestDumpMaster:
         o = dump.Options(setheaders=[(".*", "one", "two")])
         m = dump.DumpMaster(None, o, outfile=cs)
         f = self._cycle(m, "content")
-        assert f.request.headers["one"] == ["two"]
+        assert f.request.headers["one"] == "two"
 
     def test_basic(self):
         for i in (1, 2, 3):
diff --git a/test/test_filt.py b/test/test_filt.py
index aeec24857..76e107103 100644
--- a/test/test_filt.py
+++ b/test/test_filt.py
@@ -1,8 +1,8 @@
 import cStringIO
-from netlib import odict
 from libmproxy import filt, flow
 from libmproxy.protocol import http
 from libmproxy.models import Error
+from netlib.http import Headers
 import tutils
 
 
@@ -76,8 +76,7 @@ class TestParsing:
 
 class TestMatching:
     def req(self):
-        headers = odict.ODictCaseless()
-        headers["header"] = ["qvalue"]
+        headers = Headers(header="qvalue")
         req = http.HTTPRequest(
             "absolute",
             "GET",
@@ -98,8 +97,7 @@ class TestMatching:
     def resp(self):
         f = self.req()
 
-        headers = odict.ODictCaseless()
-        headers["header_response"] = ["svalue"]
+        headers = Headers([["header_response", "svalue"]])
         f.response = http.HTTPResponse(
             (1,
              1),
@@ -123,7 +121,7 @@ class TestMatching:
     def test_asset(self):
         s = self.resp()
         assert not self.q("~a", s)
-        s.response.headers["content-type"] = ["text/javascript"]
+        s.response.headers["content-type"] = "text/javascript"
         assert self.q("~a", s)
 
     def test_fcontenttype(self):
@@ -132,16 +130,16 @@ class TestMatching:
         assert not self.q("~t content", q)
         assert not self.q("~t content", s)
 
-        q.request.headers["content-type"] = ["text/json"]
+        q.request.headers["content-type"] = "text/json"
         assert self.q("~t json", q)
         assert self.q("~tq json", q)
         assert not self.q("~ts json", q)
 
-        s.response.headers["content-type"] = ["text/json"]
+        s.response.headers["content-type"] = "text/json"
         assert self.q("~t json", s)
 
         del s.response.headers["content-type"]
-        s.request.headers["content-type"] = ["text/json"]
+        s.request.headers["content-type"] = "text/json"
         assert self.q("~t json", s)
         assert self.q("~tq json", s)
         assert not self.q("~ts json", s)
diff --git a/test/test_flow.py b/test/test_flow.py
index 9cce26b35..c93beca40 100644
--- a/test/test_flow.py
+++ b/test/test_flow.py
@@ -8,7 +8,7 @@ import mock
 
 import netlib.utils
 from netlib import odict
-from netlib.http.semantics import CONTENT_MISSING, HDR_FORM_URLENCODED
+from netlib.http.semantics import CONTENT_MISSING, HDR_FORM_URLENCODED, Headers
 from libmproxy import filt, protocol, controller, tnetstring, flow
 from libmproxy.models import Error, Flow, HTTPRequest, HTTPResponse, HTTPFlow, decoded
 from libmproxy.proxy.config import HostMatcher
@@ -34,7 +34,7 @@ def test_app_registry():
     r.host = "domain2"
     r.port = 80
     assert not ar.get(r)
-    r.headers["host"] = ["domain"]
+    r.headers["host"] = "domain"
     assert ar.get(r)
 
 
@@ -42,7 +42,7 @@ class TestStickyCookieState:
     def _response(self, cookie, host):
         s = flow.StickyCookieState(filt.parse(".*"))
         f = tutils.tflow(req=netlib.tutils.treq(host=host, port=80), resp=True)
-        f.response.headers["Set-Cookie"] = [cookie]
+        f.response.headers["Set-Cookie"] = cookie
         s.handle_response(f)
         return s, f
 
@@ -75,13 +75,13 @@ class TestStickyAuthState:
     def test_handle_response(self):
         s = flow.StickyAuthState(filt.parse(".*"))
         f = tutils.tflow(resp=True)
-        f.request.headers["authorization"] = ["foo"]
+        f.request.headers["authorization"] = "foo"
         s.handle_request(f)
         assert "address" in s.hosts
 
         f = tutils.tflow(resp=True)
         s.handle_request(f)
-        assert f.request.headers["authorization"] == ["foo"]
+        assert f.request.headers["authorization"] == "foo"
 
 
 class TestClientPlaybackState:
@@ -133,7 +133,7 @@ class TestServerPlaybackState:
 
         assert s._hash(r)
         assert s._hash(r) == s._hash(r2)
-        r.request.headers["foo"] = ["bar"]
+        r.request.headers["foo"] = "bar"
         assert s._hash(r) == s._hash(r2)
         r.request.path = "voing"
         assert s._hash(r) != s._hash(r2)
@@ -153,12 +153,12 @@ class TestServerPlaybackState:
             None,
             False)
         r = tutils.tflow(resp=True)
-        r.request.headers["foo"] = ["bar"]
+        r.request.headers["foo"] = "bar"
         r2 = tutils.tflow(resp=True)
         assert not s._hash(r) == s._hash(r2)
-        r2.request.headers["foo"] = ["bar"]
+        r2.request.headers["foo"] = "bar"
         assert s._hash(r) == s._hash(r2)
-        r2.request.headers["oink"] = ["bar"]
+        r2.request.headers["oink"] = "bar"
         assert s._hash(r) == s._hash(r2)
 
         r = tutils.tflow(resp=True)
@@ -167,10 +167,10 @@ class TestServerPlaybackState:
 
     def test_load(self):
         r = tutils.tflow(resp=True)
-        r.request.headers["key"] = ["one"]
+        r.request.headers["key"] = "one"
 
         r2 = tutils.tflow(resp=True)
-        r2.request.headers["key"] = ["two"]
+        r2.request.headers["key"] = "two"
 
         s = flow.ServerPlaybackState(
             None, [
@@ -179,21 +179,21 @@ class TestServerPlaybackState:
         assert len(s.fmap.keys()) == 1
 
         n = s.next_flow(r)
-        assert n.request.headers["key"] == ["one"]
+        assert n.request.headers["key"] == "one"
         assert s.count() == 1
 
         n = s.next_flow(r)
-        assert n.request.headers["key"] == ["two"]
+        assert n.request.headers["key"] == "two"
         assert s.count() == 0
 
         assert not s.next_flow(r)
 
     def test_load_with_nopop(self):
         r = tutils.tflow(resp=True)
-        r.request.headers["key"] = ["one"]
+        r.request.headers["key"] = "one"
 
         r2 = tutils.tflow(resp=True)
-        r2.request.headers["key"] = ["two"]
+        r2.request.headers["key"] = "two"
 
         s = flow.ServerPlaybackState(
             None, [
@@ -224,12 +224,10 @@ class TestServerPlaybackState:
             None, [], False, False, None, False, [
                 "param1", "param2"], False)
         r = tutils.tflow(resp=True)
-        r.request.headers[
-            "Content-Type"] = ["application/x-www-form-urlencoded"]
+        r.request.headers["Content-Type"] = "application/x-www-form-urlencoded"
         r.request.content = "paramx=x&param1=1"
         r2 = tutils.tflow(resp=True)
-        r2.request.headers[
-            "Content-Type"] = ["application/x-www-form-urlencoded"]
+        r2.request.headers["Content-Type"] = "application/x-www-form-urlencoded"
         r2.request.content = "paramx=x&param1=1"
         # same parameters
         assert s._hash(r) == s._hash(r2)
@@ -254,10 +252,10 @@ class TestServerPlaybackState:
             None, [], False, False, None, False, [
                 "param1", "param2"], False)
         r = tutils.tflow(resp=True)
-        r.request.headers["Content-Type"] = ["application/json"]
+        r.request.headers["Content-Type"] = "application/json"
         r.request.content = '{"param1":"1"}'
         r2 = tutils.tflow(resp=True)
-        r2.request.headers["Content-Type"] = ["application/json"]
+        r2.request.headers["Content-Type"] = "application/json"
         r2.request.content = '{"param1":"1"}'
         # same content
         assert s._hash(r) == s._hash(r2)
@@ -271,12 +269,10 @@ class TestServerPlaybackState:
             None, [], False, False, None, True, [
                 "param1", "param2"], False)
         r = tutils.tflow(resp=True)
-        r.request.headers[
-            "Content-Type"] = ["application/x-www-form-urlencoded"]
+        r.request.headers["Content-Type"] = "application/x-www-form-urlencoded"
         r.request.content = "paramx=y"
         r2 = tutils.tflow(resp=True)
-        r2.request.headers[
-            "Content-Type"] = ["application/x-www-form-urlencoded"]
+        r2.request.headers["Content-Type"] = "application/x-www-form-urlencoded"
         r2.request.content = "paramx=x"
         # same parameters
         assert s._hash(r) == s._hash(r2)
@@ -460,17 +456,17 @@ class TestFlow:
 
     def test_replace(self):
         f = tutils.tflow(resp=True)
-        f.request.headers["foo"] = ["foo"]
+        f.request.headers["foo"] = "foo"
         f.request.content = "afoob"
 
-        f.response.headers["foo"] = ["foo"]
+        f.response.headers["foo"] = "foo"
         f.response.content = "afoob"
 
         assert f.replace("foo", "bar") == 6
 
-        assert f.request.headers["bar"] == ["bar"]
+        assert f.request.headers["bar"] == "bar"
         assert f.request.content == "abarb"
-        assert f.response.headers["bar"] == ["bar"]
+        assert f.response.headers["bar"] == "bar"
         assert f.response.content == "abarb"
 
     def test_replace_encoded(self):
@@ -938,14 +934,14 @@ class TestFlowMaster:
 
         fm.set_stickycookie(".*")
         f = tutils.tflow(resp=True)
-        f.response.headers["set-cookie"] = ["foo=bar"]
+        f.response.headers["set-cookie"] = "foo=bar"
         fm.handle_request(f)
         fm.handle_response(f)
         assert fm.stickycookie_state.jar
         assert not "cookie" in f.request.headers
         f = f.copy()
         fm.handle_request(f)
-        assert f.request.headers["cookie"] == ["foo=bar"]
+        assert f.request.headers["cookie"] == "foo=bar"
 
     def test_stickyauth(self):
         s = flow.State()
@@ -958,14 +954,14 @@ class TestFlowMaster:
 
         fm.set_stickyauth(".*")
         f = tutils.tflow(resp=True)
-        f.request.headers["authorization"] = ["foo"]
+        f.request.headers["authorization"] = "foo"
         fm.handle_request(f)
 
         f = tutils.tflow(resp=True)
         assert fm.stickyauth_state.hosts
         assert not "authorization" in f.request.headers
         fm.handle_request(f)
-        assert f.request.headers["authorization"] == ["foo"]
+        assert f.request.headers["authorization"] == "foo"
 
     def test_stream(self):
         with tutils.tmpdir() as tdir:
@@ -1022,7 +1018,7 @@ class TestRequest:
         assert r.url == "https://address:22/path"
 
         assert r.pretty_url(True) == "https://address:22/path"
-        r.headers["Host"] = ["foo.com"]
+        r.headers["Host"] = "foo.com"
         assert r.pretty_url(False) == "https://address:22/path"
         assert r.pretty_url(True) == "https://foo.com:22/path"
 
@@ -1048,19 +1044,17 @@ class TestRequest:
     def test_getset_form_urlencoded(self):
         d = odict.ODict([("one", "two"), ("three", "four")])
         r = HTTPRequest.wrap(netlib.tutils.treq(content=netlib.utils.urlencode(d.lst)))
-        r.headers["content-type"] = [HDR_FORM_URLENCODED]
+        r.headers["content-type"] = HDR_FORM_URLENCODED
         assert r.get_form_urlencoded() == d
 
         d = odict.ODict([("x", "y")])
         r.set_form_urlencoded(d)
         assert r.get_form_urlencoded() == d
 
-        r.headers["content-type"] = ["foo"]
+        r.headers["content-type"] = "foo"
         assert not r.get_form_urlencoded()
 
     def test_getset_query(self):
-        h = odict.ODictCaseless()
-
         r = HTTPRequest.wrap(netlib.tutils.treq())
         r.path = "/foo?x=y&a=b"
         q = r.get_query()
@@ -1083,11 +1077,10 @@ class TestRequest:
         assert r.get_query() == qv
 
     def test_anticache(self):
-        h = odict.ODictCaseless()
         r = HTTPRequest.wrap(netlib.tutils.treq())
-        r.headers = h
-        h["if-modified-since"] = ["test"]
-        h["if-none-match"] = ["test"]
+        r.headers = Headers()
+        r.headers["if-modified-since"] = "test"
+        r.headers["if-none-match"] = "test"
         r.anticache()
         assert not "if-modified-since" in r.headers
         assert not "if-none-match" in r.headers
@@ -1095,25 +1088,29 @@ class TestRequest:
     def test_replace(self):
         r = HTTPRequest.wrap(netlib.tutils.treq())
         r.path = "path/foo"
-        r.headers["Foo"] = ["fOo"]
+        r.headers["Foo"] = "fOo"
         r.content = "afoob"
         assert r.replace("foo(?i)", "boo") == 4
         assert r.path == "path/boo"
         assert not "foo" in r.content
-        assert r.headers["boo"] == ["boo"]
+        assert r.headers["boo"] == "boo"
 
     def test_constrain_encoding(self):
         r = HTTPRequest.wrap(netlib.tutils.treq())
-        r.headers["accept-encoding"] = ["gzip", "oink"]
+        r.headers["accept-encoding"] = "gzip, oink"
+        r.constrain_encoding()
+        assert "oink" not in r.headers["accept-encoding"]
+
+        r.headers.set_all("accept-encoding", ["gzip", "oink"])
         r.constrain_encoding()
         assert "oink" not in r.headers["accept-encoding"]
 
     def test_decodeencode(self):
         r = HTTPRequest.wrap(netlib.tutils.treq())
-        r.headers["content-encoding"] = ["identity"]
+        r.headers["content-encoding"] = "identity"
         r.content = "falafel"
         r.decode()
-        assert not r.headers["content-encoding"]
+        assert "content-encoding" not in r.headers
         assert r.content == "falafel"
 
         r = HTTPRequest.wrap(netlib.tutils.treq())
@@ -1121,26 +1118,26 @@ class TestRequest:
         assert not r.decode()
 
         r = HTTPRequest.wrap(netlib.tutils.treq())
-        r.headers["content-encoding"] = ["identity"]
+        r.headers["content-encoding"] = "identity"
         r.content = "falafel"
         r.encode("identity")
-        assert r.headers["content-encoding"] == ["identity"]
+        assert r.headers["content-encoding"] == "identity"
         assert r.content == "falafel"
 
         r = HTTPRequest.wrap(netlib.tutils.treq())
-        r.headers["content-encoding"] = ["identity"]
+        r.headers["content-encoding"] = "identity"
         r.content = "falafel"
         r.encode("gzip")
-        assert r.headers["content-encoding"] == ["gzip"]
+        assert r.headers["content-encoding"] == "gzip"
         assert r.content != "falafel"
         r.decode()
-        assert not r.headers["content-encoding"]
+        assert "content-encoding" not in r.headers
         assert r.content == "falafel"
 
     def test_get_decoded_content(self):
         r = HTTPRequest.wrap(netlib.tutils.treq())
         r.content = None
-        r.headers["content-encoding"] = ["identity"]
+        r.headers["content-encoding"] = "identity"
         assert r.get_decoded_content() == None
 
         r.content = "falafel"
@@ -1148,11 +1145,9 @@ class TestRequest:
         assert r.get_decoded_content() == "falafel"
 
     def test_get_content_type(self):
-        h = odict.ODictCaseless()
-        h["Content-Type"] = ["text/plain"]
         resp = HTTPResponse.wrap(netlib.tutils.tresp())
-        resp.headers = h
-        assert resp.headers.get_first("content-type") == "text/plain"
+        resp.headers = Headers(content_type="text/plain")
+        assert resp.headers["content-type"] == "text/plain"
 
 
 class TestResponse:
@@ -1165,19 +1160,18 @@ class TestResponse:
     def test_refresh(self):
         r = HTTPResponse.wrap(netlib.tutils.tresp())
         n = time.time()
-        r.headers["date"] = [email.utils.formatdate(n)]
+        r.headers["date"] = email.utils.formatdate(n)
         pre = r.headers["date"]
         r.refresh(n)
         assert pre == r.headers["date"]
         r.refresh(n + 60)
 
-        d = email.utils.parsedate_tz(r.headers["date"][0])
+        d = email.utils.parsedate_tz(r.headers["date"])
         d = email.utils.mktime_tz(d)
         # Weird that this is not exact...
         assert abs(60 - (d - n)) <= 1
 
-        r.headers[
-            "set-cookie"] = ["MOO=BAR; Expires=Tue, 08-Mar-2011 00:20:38 GMT; Path=foo.com; Secure"]
+        r.headers["set-cookie"] = "MOO=BAR; Expires=Tue, 08-Mar-2011 00:20:38 GMT; Path=foo.com; Secure"
         r.refresh()
 
     def test_refresh_cookie(self):
@@ -1192,47 +1186,45 @@ class TestResponse:
 
     def test_replace(self):
         r = HTTPResponse.wrap(netlib.tutils.tresp())
-        r.headers["Foo"] = ["fOo"]
+        r.headers["Foo"] = "fOo"
         r.content = "afoob"
         assert r.replace("foo(?i)", "boo") == 3
         assert not "foo" in r.content
-        assert r.headers["boo"] == ["boo"]
+        assert r.headers["boo"] == "boo"
 
     def test_decodeencode(self):
         r = HTTPResponse.wrap(netlib.tutils.tresp())
-        r.headers["content-encoding"] = ["identity"]
+        r.headers["content-encoding"] = "identity"
         r.content = "falafel"
         assert r.decode()
-        assert not r.headers["content-encoding"]
+        assert "content-encoding" not in r.headers
         assert r.content == "falafel"
 
         r = HTTPResponse.wrap(netlib.tutils.tresp())
-        r.headers["content-encoding"] = ["identity"]
+        r.headers["content-encoding"] = "identity"
         r.content = "falafel"
         r.encode("identity")
-        assert r.headers["content-encoding"] == ["identity"]
+        assert r.headers["content-encoding"] == "identity"
         assert r.content == "falafel"
 
         r = HTTPResponse.wrap(netlib.tutils.tresp())
-        r.headers["content-encoding"] = ["identity"]
+        r.headers["content-encoding"] = "identity"
         r.content = "falafel"
         r.encode("gzip")
-        assert r.headers["content-encoding"] == ["gzip"]
+        assert r.headers["content-encoding"] == "gzip"
         assert r.content != "falafel"
         assert r.decode()
-        assert not r.headers["content-encoding"]
+        assert "content-encoding" not in r.headers
         assert r.content == "falafel"
 
-        r.headers["content-encoding"] = ["gzip"]
+        r.headers["content-encoding"] = "gzip"
         assert not r.decode()
         assert r.content == "falafel"
 
     def test_get_content_type(self):
-        h = odict.ODictCaseless()
-        h["Content-Type"] = ["text/plain"]
         resp = HTTPResponse.wrap(netlib.tutils.tresp())
-        resp.headers = h
-        assert resp.headers.get_first("content-type") == "text/plain"
+        resp.headers = Headers(content_type="text/plain")
+        assert resp.headers["content-type"] == "text/plain"
 
 
 class TestError:
@@ -1276,12 +1268,12 @@ class TestClientConnection:
 def test_decoded():
     r = HTTPRequest.wrap(netlib.tutils.treq())
     assert r.content == "content"
-    assert not r.headers["content-encoding"]
+    assert "content-encoding" not in r.headers
     r.encode("gzip")
     assert r.headers["content-encoding"]
     assert r.content != "content"
     with decoded(r):
-        assert not r.headers["content-encoding"]
+        assert "content-encoding" not in r.headers
         assert r.content == "content"
     assert r.headers["content-encoding"]
     assert r.content != "content"
@@ -1378,18 +1370,18 @@ def test_setheaders():
     h.add("~s", "one", "two")
     h.add("~s", "one", "three")
     f = tutils.tflow(resp=True)
-    f.request.headers["one"] = ["xxx"]
-    f.response.headers["one"] = ["xxx"]
+    f.request.headers["one"] = "xxx"
+    f.response.headers["one"] = "xxx"
     h.run(f)
-    assert f.request.headers["one"] == ["xxx"]
-    assert f.response.headers["one"] == ["two", "three"]
+    assert f.request.headers["one"] == "xxx"
+    assert f.response.headers.get_all("one") == ["two", "three"]
 
     h.clear()
     h.add("~q", "one", "two")
     h.add("~q", "one", "three")
     f = tutils.tflow()
-    f.request.headers["one"] = ["xxx"]
+    f.request.headers["one"] = "xxx"
     h.run(f)
-    assert f.request.headers["one"] == ["two", "three"]
+    assert f.request.headers.get_all("one") == ["two", "three"]
 
     assert not h.add("~", "foo", "bar")
diff --git a/test/test_protocol_http.py b/test/test_protocol_http.py
index cd0f77fa7..f53d43cfa 100644
--- a/test/test_protocol_http.py
+++ b/test/test_protocol_http.py
@@ -5,7 +5,6 @@ from mock import MagicMock
 
 from libmproxy.protocol.http import *
 import netlib.http
-from netlib import odict
 from netlib.http import http1
 from netlib.http.semantics import CONTENT_MISSING
 
diff --git a/test/test_server.py b/test/test_server.py
index a1259b7fc..829b5f0ab 100644
--- a/test/test_server.py
+++ b/test/test_server.py
@@ -623,8 +623,7 @@ class MasterRedirectRequest(tservers.TestMaster):
 
     def handle_response(self, f):
         f.response.content = str(f.client_conn.address.port)
-        f.response.headers[
-            "server-conn-id"] = [str(f.server_conn.source_address.port)]
+        f.response.headers["server-conn-id"] = str(f.server_conn.source_address.port)
         super(MasterRedirectRequest, self).handle_response(f)
 
 
@@ -721,7 +720,7 @@ class TestStreamRequest(tservers.HTTPProxTest):
         protocol = http.http1.HTTP1Protocol(rfile=fconn)
         resp = protocol.read_response("GET", None, include_body=False)
 
-        assert resp.headers["Transfer-Encoding"][0] == 'chunked'
+        assert resp.headers["Transfer-Encoding"] == 'chunked'
         assert resp.status_code == 200
 
         chunks = list(protocol.read_http_body_chunked(
@@ -743,7 +742,7 @@ class TestFakeResponse(tservers.HTTPProxTest):
 
     def test_fake(self):
         f = self.pathod("200")
-        assert "header_response" in f.headers.keys()
+        assert "header_response" in f.headers
 
 
 class TestServerConnect(tservers.HTTPProxTest):
diff --git a/test/test_utils.py b/test/test_utils.py
index 0cda23b40..d2bd97e14 100644
--- a/test/test_utils.py
+++ b/test/test_utils.py
@@ -1,6 +1,5 @@
 import json
 from libmproxy import utils
-from netlib import odict
 import tutils
 
 utils.CERT_SLEEP_TIME = 0