Drop pkg:charcode usage in dev_dependencies

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2bb3d55..60da466 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md

@@ -1,3 +1,5 @@
+## 4.0.2-dev
+
 ## 4.0.1
 
 * Remove dependency on `package:charcode`.

diff --git a/lib/src/chunked_coding/charcodes.dart b/lib/src/chunked_coding/charcodes.dart
index a7a8519..4d5e451 100644
--- a/lib/src/chunked_coding/charcodes.dart
+++ b/lib/src/chunked_coding/charcodes.dart

@@ -11,8 +11,23 @@
 /// Character `0`.
 const int $0 = 0x30;
 
-/// Character `9`.
-const int $9 = 0x39;
+/// Character `1`.
+const int $1 = 0x31;
+
+/// Character `3`.
+const int $3 = 0x33;
+
+/// Character `4`.
+const int $4 = 0x34;
+
+/// Character `7`.
+const int $7 = 0x37;
+
+/// Character `A`.
+const int $A = 0x41;
+
+/// Character `q`.
+const int $q = 0x71;
 
 /// Character `a`.
 const int $a = 0x61;

diff --git a/pubspec.yaml b/pubspec.yaml
index 9ceb428..a768409 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml

@@ -1,5 +1,5 @@
 name: http_parser
-version: 4.0.1
+version: 4.0.2-dev
 description: >-
   A platform-independent package for parsing and serializing HTTP formats.
 repository: https://github.com/dart-lang/http_parser
@@ -14,6 +14,5 @@
   typed_data: ^1.3.0
 
 dev_dependencies:
-  charcode: ^1.2.0
   lints: ^1.0.0
   test: ^1.16.0

diff --git a/test/chunked_coding_test.dart b/test/chunked_coding_test.dart
index 93b4de4..476a2d2 100644
--- a/test/chunked_coding_test.dart
+++ b/test/chunked_coding_test.dart

@@ -5,8 +5,8 @@
 import 'dart:async';
 import 'dart:convert';
 
-import 'package:charcode/charcode.dart';
 import 'package:http_parser/http_parser.dart';
+import 'package:http_parser/src/chunked_coding/charcodes.dart';
 import 'package:test/test.dart';
 
 void main() {