diff --git a/mitmproxy/net/http/cookies.py b/mitmproxy/net/http/cookies.py
index 32032f5f2..7bef87579 100644
--- a/mitmproxy/net/http/cookies.py
+++ b/mitmproxy/net/http/cookies.py
@@ -114,12 +114,11 @@ def _read_cookie_pairs(s, off=0):
         lhs, off = _read_key(s, off)
         lhs = lhs.lstrip()
 
-        if lhs is not None:
-            rhs = None
-            if off < len(s) and s[off] == "=":
-                rhs, off = _read_value(s, off + 1, ";")
-            if rhs or lhs:
-                pairs.append([lhs, rhs])
+        rhs = ""
+        if off < len(s) and s[off] == "=":
+            rhs, off = _read_value(s, off + 1, ";")
+        if rhs or lhs:
+            pairs.append([lhs, rhs])
 
         off += 1
 
@@ -143,26 +142,25 @@ def _read_set_cookie_pairs(s: str, off=0) -> Tuple[List[TPairs], int]:
         lhs, off = _read_key(s, off, ";=,")
         lhs = lhs.lstrip()
 
-        if lhs is not None:
-            rhs = None
-            if off < len(s) and s[off] == "=":
-                rhs, off = _read_value(s, off + 1, ";,")
+        rhs = ""
+        if off < len(s) and s[off] == "=":
+            rhs, off = _read_value(s, off + 1, ";,")
 
-                # Special handling of attributes
-                if lhs.lower() == "expires":
-                    # 'expires' values can contain commas in them so they need to
-                    # be handled separately.
+            # Special handling of attributes
+            if lhs.lower() == "expires":
+                # 'expires' values can contain commas in them so they need to
+                # be handled separately.
 
-                    # We actually bank on the fact that the expires value WILL
-                    # contain a comma. Things will fail, if they don't.
+                # We actually bank on the fact that the expires value WILL
+                # contain a comma. Things will fail, if they don't.
 
-                    # '3' is just a heuristic we use to determine whether we've
-                    # only read a part of the expires value and we should read more.
-                    if len(rhs) <= 3:
-                        trail, off = _read_value(s, off + 1, ";,")
-                        rhs = rhs + "," + trail
-            if rhs or lhs:
-                pairs.append([lhs, rhs])
+                # '3' is just a heuristic we use to determine whether we've
+                # only read a part of the expires value and we should read more.
+                if len(rhs) <= 3:
+                    trail, off = _read_value(s, off + 1, ";,")
+                    rhs = rhs + "," + trail
+        if rhs or lhs:
+            pairs.append([lhs, rhs])
 
             # comma marks the beginning of a new cookie
             if off < len(s) and s[off] == ",":
@@ -196,13 +194,10 @@ def _format_pairs(pairs, specials=(), sep="; "):
     """
     vals = []
     for k, v in pairs:
-        if v is None:
-            vals.append(k)
-        else:
-            if k.lower() not in specials and _has_special(v):
-                v = ESCAPE.sub(r"\\\1", v)
-                v = '"%s"' % v
-            vals.append("%s=%s" % (k, v))
+        if k.lower() not in specials and _has_special(v):
+            v = ESCAPE.sub(r"\\\1", v)
+            v = '"%s"' % v
+        vals.append("%s=%s" % (k, v))
     return sep.join(vals)
 
 
diff --git a/test/mitmproxy/net/http/test_cookies.py b/test/mitmproxy/net/http/test_cookies.py
index 496f595b2..e12b0f005 100644
--- a/test/mitmproxy/net/http/test_cookies.py
+++ b/test/mitmproxy/net/http/test_cookies.py
@@ -20,7 +20,7 @@ cookie_pairs = [
     ],
     [
         "one",
-        [["one", None]]
+        [["one", ""]]
     ],
     [
         "one=uno; two=due",
@@ -40,7 +40,7 @@ cookie_pairs = [
     ],
     [
         "one=uno; two; three=tre",
-        [["one", "uno"], ["two", None], ["three", "tre"]]
+        [["one", "uno"], ["two", ""], ["three", "tre"]]
     ],
     [
         "_lvs2=zHai1+Hq+Tc2vmc2r4GAbdOI5Jopg3EwsdUT9g=; "
@@ -82,9 +82,13 @@ def test_read_quoted_string():
 
 def test_read_cookie_pairs():
     vals = [
+        [
+            "=uno",
+            [["", "uno"]]
+        ],
         [
             "one",
-            [["one", None]]
+            [["one", ""]]
         ],
         [
             "one=two",
@@ -104,7 +108,7 @@ def test_read_cookie_pairs():
         ],
         [
             'one="two"; three=four; five',
-            [["one", "two"], ["three", "four"], ["five", None]]
+            [["one", "two"], ["three", "four"], ["five", ""]]
         ],
         [
             'one="\\"two"; three=four',
@@ -138,6 +142,12 @@ def test_cookie_roundtrips():
 
 def test_parse_set_cookie_pairs():
     pairs = [
+        [
+            "=uno",
+            [[
+                ["", "uno"]
+            ]]
+        ],
         [
             "one=uno",
             [[
@@ -154,7 +164,7 @@ def test_parse_set_cookie_pairs():
             "one=uno; foo",
             [[
                 ["one", "uno"],
-                ["foo", None]
+                ["foo", ""]
             ]]
         ],
         [
@@ -203,6 +213,12 @@ def test_parse_set_cookie_header():
         [
             ";", []
         ],
+        [
+            "=uno",
+            [
+                ("", "uno", ())
+            ]
+        ],
         [
             "one=uno",
             [
diff --git a/test/mitmproxy/net/http/test_response.py b/test/mitmproxy/net/http/test_response.py
index af35bab35..f3470384b 100644
--- a/test/mitmproxy/net/http/test_response.py
+++ b/test/mitmproxy/net/http/test_response.py
@@ -113,7 +113,7 @@ class TestResponseUtils:
         assert attrs["domain"] == "example.com"
         assert attrs["expires"] == "Wed Oct  21 16:29:41 2015"
         assert attrs["path"] == "/"
-        assert attrs["httponly"] is None
+        assert attrs["httponly"] == ""
 
     def test_get_cookies_no_value(self):
         resp = tresp()