diff --git a/CHANGELOG.md b/CHANGELOG.md
index fda523921d9..aaac854e089 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,15 @@
 
 ### Core library
 
+#### `dart:io`
+
+* Fixed `Cookie` class interoperability with certain websites by allowing the
+  cookie values to be the empty string (Issue [35804][]) and not stripping
+  double quotes from the value (Issue [33327][]) in accordance with RFC 6265.
+
+[33327]: https://github.com/dart-lang/sdk/issues/33327
+[35804]: https://github.com/dart-lang/sdk/issues/35804
+
 ### Dart VM
 
 ### Tools
diff --git a/sdk/lib/_http/http_headers.dart b/sdk/lib/_http/http_headers.dart
index ea5eafff067..dc9ff8476a6 100644
--- a/sdk/lib/_http/http_headers.dart
+++ b/sdk/lib/_http/http_headers.dart
@@ -982,14 +982,24 @@ class _Cookie implements Cookie {
           codeUnit >= 127 ||
           separators.indexOf(name[i]) >= 0) {
         throw new FormatException(
-            "Invalid character in cookie name, code unit: '$codeUnit'");
+            "Invalid character in cookie name, code unit: '$codeUnit'",
+            name,
+            i);
       }
     }
 
-    if (value[0] == '"' && value[value.length - 1] == '"') {
-      value = value.substring(1, value.length - 1);
+    // Per RFC 6265, consider surrounding "" as part of the value, but otherwise
+    // double quotes are not allowed.
+    int start = 0;
+    int end = value.length;
+    if (2 <= value.length &&
+        value.codeUnits[start] == 0x22 &&
+        value.codeUnits[end - 1] == 0x22) {
+      start++;
+      end--;
     }
-    for (int i = 0; i < value.length; i++) {
+
+    for (int i = start; i < end; i++) {
       int codeUnit = value.codeUnits[i];
       if (!(codeUnit == 0x21 ||
           (codeUnit >= 0x23 && codeUnit <= 0x2B) ||
@@ -997,7 +1007,9 @@ class _Cookie implements Cookie {
           (codeUnit >= 0x3C && codeUnit <= 0x5B) ||
           (codeUnit >= 0x5D && codeUnit <= 0x7E))) {
         throw new FormatException(
-            "Invalid character in cookie value, code unit: '$codeUnit'");
+            "Invalid character in cookie value, code unit: '$codeUnit'",
+            value,
+            i);
       }
     }
   }
diff --git a/tests/standalone_2/io/http_cookie_test.dart b/tests/standalone_2/io/http_cookie_test.dart
index 50cad66d990..bfe9302aeb2 100644
--- a/tests/standalone_2/io/http_cookie_test.dart
+++ b/tests/standalone_2/io/http_cookie_test.dart
@@ -2,8 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import "dart:async";
 import "dart:io";
+
 import "package:expect/expect.dart";
 
 void testCookies() {
@@ -59,12 +59,28 @@ void testCookies() {
 }
 
 void testValidateCookieWithDoubleQuotes() {
-  try {
-    Cookie cookie = Cookie('key', '"double-quoted-value"');
-  } catch (e) {
-    Expect.fail("Unexpected error $e.\n"
-        "Unable to parse cookie with value in double-quote characters.");
-  }
+  Expect.equals(Cookie('key', 'value').toString(), 'key=value; HttpOnly');
+  Expect.equals(Cookie('key', '').toString(), 'key=; HttpOnly');
+  Expect.equals(Cookie('key', '""').toString(), 'key=""; HttpOnly');
+  Expect.equals(Cookie('key', '"value"').toString(), 'key="value"; HttpOnly');
+  Expect.equals(Cookie.fromSetCookieValue('key=value; HttpOnly').toString(),
+      'key=value; HttpOnly');
+  Expect.equals(
+      Cookie.fromSetCookieValue('key=; HttpOnly').toString(), 'key=; HttpOnly');
+  Expect.equals(Cookie.fromSetCookieValue('key=""; HttpOnly').toString(),
+      'key=""; HttpOnly');
+  Expect.equals(Cookie.fromSetCookieValue('key="value"; HttpOnly').toString(),
+      'key="value"; HttpOnly');
+  Expect.throwsFormatException(() => Cookie('key', '"'));
+  Expect.throwsFormatException(() => Cookie('key', '"""'));
+  Expect.throwsFormatException(() => Cookie('key', '"x""'));
+  Expect.throwsFormatException(() => Cookie('key', '"x"y"'));
+  Expect.throwsFormatException(
+      () => Cookie.fromSetCookieValue('key="; HttpOnly'));
+  Expect.throwsFormatException(
+      () => Cookie.fromSetCookieValue('key="""; HttpOnly'));
+  Expect.throwsFormatException(
+      () => Cookie.fromSetCookieValue('key="x""; HttpOnly'));
 }
 
 void main() {
diff --git a/tests/standalone_2/standalone_2_kernel.status b/tests/standalone_2/standalone_2_kernel.status
index 69cdf980f41..1441048b7f2 100644
--- a/tests/standalone_2/standalone_2_kernel.status
+++ b/tests/standalone_2/standalone_2_kernel.status
@@ -106,7 +106,6 @@ io/file_fuzz_test: RuntimeError, Pass
 io/http_client_connect_test: Skip # Flaky.
 io/http_close_test: Crash
 io/http_content_length_test: Skip # Flaky.
-io/http_cookie_test: Skip # Flaky
 io/http_proxy_advanced_test: Skip # Flaky
 io/http_proxy_test: Skip # Flaky.
 io/http_response_deadline_test: Skip # Flaky.