diff --git a/lib/rack.rb b/lib/rack.rb
index d00b96667..69780545e 100644
--- a/lib/rack.rb
+++ b/lib/rack.rb
@@ -41,7 +41,6 @@ module Rack
   autoload :MethodOverride, "rack/method_override"
   autoload :Mime, "rack/mime"
   autoload :NullLogger, "rack/null_logger"
-  autoload :QueryParser, "rack/query_parser"
   autoload :Recursive, "rack/recursive"
   autoload :Reloader, "rack/reloader"
   autoload :RewindableInput, "rack/rewindable_input"
diff --git a/lib/rack/query_parser.rb b/lib/rack/query_parser.rb
index 525900f7b..1c05ae828 100644
--- a/lib/rack/query_parser.rb
+++ b/lib/rack/query_parser.rb
@@ -1,7 +1,6 @@
 # frozen_string_literal: true
 
 require_relative 'bad_request'
-require 'uri'
 
 module Rack
   class QueryParser
@@ -112,14 +111,6 @@ def normalize_params(params, name, v, _depth=nil)
       _normalize_params(params, name, v, 0)
     end
 
-    # This value is used by default when a parameter is missing (nil). This
-    # usually happens when a parameter is specified without an `=value` part.
-    # The default value is an empty string, but this can be overridden by
-    # subclasses.
-    def missing_value
-      String.new
-    end
-
     private def _normalize_params(params, name, v, depth)
       raise ParamsTooDeepError if depth >= param_depth_limit
 
@@ -154,7 +145,7 @@ def missing_value
 
       return if k.empty?
 
-      v ||= missing_value
+      v ||= String.new
 
       if after == ''
         if k == '[]' && depth != 0
@@ -216,8 +207,8 @@ def params_hash_has_key?(hash, key)
       true
     end
 
-    def unescape(string, encoding = Encoding::UTF_8)
-      URI.decode_www_form_component(string, encoding)
+    def unescape(s)
+      Utils.unescape(s)
     end
 
     class Params < Hash
diff --git a/test/spec_query_parser.rb b/test/spec_query_parser.rb
deleted file mode 100644
index 5f4708186..000000000
--- a/test/spec_query_parser.rb
+++ /dev/null
@@ -1,33 +0,0 @@
-# frozen_string_literal: true
-
-require_relative 'helper'
-
-separate_testing do
-  require_relative '../lib/rack/query_parser'
-end
-
-describe Rack::QueryParser do
-  def query_parser
-    @query_parser ||= Rack::QueryParser.new(Rack::QueryParser::Params, 8)
-  end
-
-  it "has a default value" do
-    assert_equal "", query_parser.missing_value
-  end
-
-  it "can normalize values with missing values" do
-    query_parser.parse_nested_query("a=a").must_equal({"a" => "a"})
-    query_parser.parse_nested_query("a=").must_equal({"a" => ""})
-    query_parser.parse_nested_query("a").must_equal({"a" => ""})
-  end
-
-  it "can override default missing value" do
-    def query_parser.missing_value
-      nil
-    end
-
-    query_parser.parse_nested_query("a=a").must_equal({"a" => "a"})
-    query_parser.parse_nested_query("a=").must_equal({"a" => ""})
-    query_parser.parse_nested_query("a").must_equal({"a" => nil})
-  end
-end