diff --git a/Gemfile b/Gemfile
index 033a820f4..7ffff1137 100644
--- a/Gemfile
+++ b/Gemfile
@@ -11,7 +11,7 @@ gem "rspec"
 gem "rubocop"
 gem "rubocop-rubycw"
 gem "rubocop-on-rbs"
-gem "json", "~> 2.10.2"
+gem "json"
 gem "json-schema"
 gem "goodcheck"
 gem 'digest'
diff --git a/Gemfile.lock b/Gemfile.lock
index 2c64c708b..76106c26f 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -55,7 +55,7 @@ GEM
       pp (>= 0.6.0)
       rdoc (>= 4.0.0)
       reline (>= 0.4.2)
-    json (2.10.2)
+    json (2.17.1)
     json-schema (6.0.0)
       addressable (~> 2.8)
       bigdecimal (~> 3.1)
@@ -201,7 +201,7 @@ DEPENDENCIES
   fileutils
   goodcheck
   irb
-  json (~> 2.10.2)
+  json
   json-schema
   memory_profiler
   minitest
diff --git a/stdlib/json/0/json.rbs b/stdlib/json/0/json.rbs
index 6d242c831..fd1c24560 100644
--- a/stdlib/json/0/json.rbs
+++ b/stdlib/json/0/json.rbs
@@ -14,9 +14,6 @@ end
 class JSON::GeneratorError < JSON::JSONError
 end
 
-class JSON::UnparserError < JSON::GeneratorError
-end
-
 # <!-- rdoc-file=ext/json/lib/json/common.rb -->
 # This exception is raised if a parser error occurs.
 #
@@ -711,8 +708,6 @@ module JSON
   #
   def self.create_id=: (_ToS create_id) -> _ToS
 
-  def self.deep_const_get: (interned path) -> untyped
-
   # <!--
   #   rdoc-file=ext/json/lib/json/common.rb
   #   - JSON.dump(obj, io = nil, limit = nil)
@@ -754,6 +749,7 @@ module JSON
   #     opts = JSON.dump_default_options
   #     opts # => {:max_nesting=>false, :allow_nan=>true}
   #
+  %a{deprecated}
   def self.dump_default_options: () -> options
 
   # <!-- rdoc-file=ext/json/lib/json/common.rb -->
@@ -761,6 +757,7 @@ module JSON
   #     opts = JSON.dump_default_options
   #     opts # => {:max_nesting=>false, :allow_nan=>true}
   #
+  %a{deprecated}
   def self.dump_default_options=: (options) -> options
 
   # <!--
@@ -778,12 +775,9 @@ module JSON
   #     # Raises SystemStackError (stack level too deep):
   #     JSON.fast_generate(a)
   #
+  %a{deprecated}
   def self?.fast_generate: (_ToJson obj, ?options opts) -> String
 
-  alias self.fast_unparse self.fast_generate
-
-  alias fast_unparse fast_generate
-
   # <!--
   #   rdoc-file=ext/json/lib/json/common.rb
   #   - JSON.generate(obj, opts = nil) -> new_string
@@ -830,14 +824,6 @@ module JSON
 
   def self.generator=: (generator generator) -> void
 
-  # <!--
-  #   rdoc-file=ext/json/lib/json/common.rb
-  #   - iconv(to, from, string)
-  # -->
-  # Encodes string using String.encode.
-  #
-  def self.iconv: (encoding to, encoding from, String string) -> String
-
   # <!--
   #   rdoc-file=ext/json/lib/json/common.rb
   #   - JSON.load(source, proc = nil, options = {}) -> object
@@ -974,7 +960,8 @@ module JSON
   #        #<Admin:0x00000000064c41f8
   #        @attributes={"type"=>"Admin", "password"=>"0wn3d"}>}
   #
-  def self?.load: (string | _ReadableIO | _Read source, ?Proc proc, ?options options) -> untyped
+  def self?.load: (string | _ReadableIO | _Read source, ?options options) -> untyped
+                | [T] (string | _ReadableIO | _Read source, ^(?) -> T, ?options options) -> T
 
   # <!--
   #   rdoc-file=ext/json/lib/json/common.rb
@@ -1003,6 +990,7 @@ module JSON
   #     opts = JSON.load_default_options
   #     opts # => {:max_nesting=>false, :allow_nan=>true, :allow_blank=>true, :create_additions=>true}
   #
+  %a{deprecated}
   def self.load_default_options: () -> options
 
   # <!-- rdoc-file=ext/json/lib/json/common.rb -->
@@ -1010,6 +998,7 @@ module JSON
   #     opts = JSON.load_default_options
   #     opts # => {:max_nesting=>false, :allow_nan=>true, :allow_blank=>true, :create_additions=>true}
   #
+  %a{deprecated}
   def self.load_default_options=: (options) -> options
 
   # <!--
@@ -1120,29 +1109,6 @@ module JSON
   #
   def self?.pretty_generate: (_ToJson obj, ?options opts) -> untyped
 
-  alias self.pretty_unparse self.pretty_generate
-
-  alias pretty_unparse pretty_generate
-
-  # Recursively calls passed *Proc* if the parsed data structure is an *Array* or
-  # *Hash*
-  #
-  def self?.recurse_proc: (untyped result) { (*untyped) -> void } -> void
-
-  # <!--
-  #   rdoc-file=ext/json/lib/json/common.rb
-  #   - restore(source, proc = nil, options = nil)
-  # -->
-  #
-  alias self.restore self.load
-
-  # <!--
-  #   rdoc-file=ext/json/lib/json/common.rb
-  #   - restore(source, proc = nil, options = nil)
-  # -->
-  #
-  alias restore load
-
   # <!-- rdoc-file=ext/json/lib/json/common.rb -->
   # Sets or Returns the JSON generator state class that is used by JSON.
   #
@@ -1152,10 +1118,6 @@ module JSON
   # Sets or Returns the JSON generator state class that is used by JSON.
   #
   def self.state=: (state) -> state
-
-  alias self.unparse self.generate
-
-  alias unparse generate
 end
 
 JSON::FAST_STATE_PROTOTYPE: JSON::state
@@ -1193,6 +1155,7 @@ module Kernel
   # Outputs *objs* to STDOUT as JSON strings in the shortest form, that is in one
   # line.
   #
+  %a{deprecated}
   def j: (*_ToJson) -> nil
 
   # <!--
@@ -1202,6 +1165,7 @@ module Kernel
   # Outputs *objs* to STDOUT as JSON strings in a pretty format, with indentation
   # and over many lines.
   #
+  %a{deprecated}
   def jj: (*_ToJson) -> nil
 
   # <!--
diff --git a/test/stdlib/json/JSONKernel_test.rb b/test/stdlib/json/JSONKernel_test.rb
index d5ac73aa3..0ecb5b2ee 100644
--- a/test/stdlib/json/JSONKernel_test.rb
+++ b/test/stdlib/json/JSONKernel_test.rb
@@ -7,28 +7,6 @@ class JSONKernelInstanceTest < Test::Unit::TestCase
   library "json"
   testing "::Kernel"
 
-  def silent
-    orig_stdout = $stdout
-    $stdout = StringIO.new
-    yield
-  ensure
-    $stdout = orig_stdout
-  end
-
-  def test_j
-    silent do
-      assert_send_type("(Integer) -> nil", self, :j, 1)
-      assert_send_type("(Array[Integer]) -> nil", self, :j, [1, 2, 3])
-    end
-  end
-
-  def test_jj
-    silent do
-      assert_send_type("(Integer) -> nil", self, :jj, 1)
-      assert_send_type("(Array[Integer]) -> nil", self, :jj, [1, 2, 3])
-    end
-  end
-
   def test_JSON
     assert_send_type("(String) -> Hash[String, Integer]", self, :JSON, '{"a": 1}')
     assert_send_type("(Array[Integer]) -> String", self, :JSON, [1, 2, 3])
diff --git a/test/stdlib/json/JSON_test.rb b/test/stdlib/json/JSON_test.rb
index 79012e629..3f151eec7 100644
--- a/test/stdlib/json/JSON_test.rb
+++ b/test/stdlib/json/JSON_test.rb
@@ -47,12 +47,6 @@ def test_create_id_eq
     assert_send_type "(String) -> String", JSON, :create_id=, "json_class"
   end
 
-  def test_deep_const_get
-    with_interned("File") do |val|
-      assert_send_type "(interned) -> singleton(File)", JSON, :deep_const_get, val
-    end
-  end
-
   def test_dump
     assert_send_type "(ToJson) -> String", JSON, :dump, ToJson.new
     assert_send_type "(ToJson, Integer) -> String", JSON, :dump, ToJson.new, 100
@@ -61,27 +55,6 @@ def test_dump
     assert_send_type "(ToJson, JsonWrite, Integer) -> JsonWrite", JSON, :dump, ToJson.new, JsonWrite.new, 100
   end
 
-  def test_dump_default_options
-    assert_send_type "() -> { max_nesting: false, allow_nan: true }", JSON, :dump_default_options
-  end
-
-  def test_dump_default_options_eq
-    assert_send_type "(max_nesting: false, allow_nan: true, allow_blank: true) -> { max_nesting: false, allow_nan: true, allow_blank: true }",
-                     JSON,
-                     :dump_default_options=,
-                     { max_nesting: false, allow_nan: true, allow_blank: true }
-  end
-
-  def test_fast_generate
-    assert_send_type "(ToJson) -> String", JSON, :fast_generate, ToJson.new
-    assert_send_type "(ToJson, indent: String) -> String", JSON, :fast_generate, ToJson.new, { indent: "\t" }
-  end
-
-  def test_fast_unparse
-    assert_send_type "(ToJson) -> String", JSON, :fast_unparse, ToJson.new
-    assert_send_type "(ToJson, indent: String) -> String", JSON, :fast_unparse, ToJson.new, { indent: "\t" }
-  end
-
   def test_generate
     assert_send_type "(ToJson) -> String", JSON, :generate, ToJson.new
     assert_send_type "(ToJson, indent: String) -> String", JSON, :generate, ToJson.new, { indent: "\t" }
@@ -95,19 +68,13 @@ def test_generator=
     assert_send_type "(singleton(JSON::Ext::Generator)) -> void", JSON, :generator=, JSON::Ext::Generator
   end
 
-  def test_iconv
-    assert_send_type "(Encoding, Encoding, String) -> String", JSON, :iconv, Encoding::UTF_8, Encoding::UTF_16, "".encode(Encoding::UTF_16)
-    assert_send_type "(String, String, String) -> String", JSON, :iconv, 'UTF-8', 'UTF-16', "".encode(Encoding::UTF_16)
-    assert_send_type "(_ToStr, _ToStr, String) -> String", JSON, :iconv, JsonToStr.new('UTF-8'), JsonToStr.new('UTF-16'), "".encode(Encoding::UTF_16)
-  end
-
   def test_load
     assert_send_type "(String) -> 42", JSON, :load, "42"
     assert_send_type "(_ToStr) -> 42", JSON, :load, JsonToStr.new("42")
     assert_send_type "(JsonToReadableIO) -> 42", JSON, :load, JsonToReadableIO.new
     assert_send_type "(JsonRead) -> 42", JSON, :load, JsonRead.new
-    assert_send_type "(String, Proc) -> 42", JSON, :load, "42", proc { }
-    assert_send_type "(String, Proc, Hash[untyped, untyped]) -> 42", JSON, :load, "42", proc { }, { alllow_nan: true }
+    assert_send_type "(String, Proc) -> 42", JSON, :load, "42", proc { |a| a }
+    assert_send_type "(String, Proc, Hash[untyped, untyped]) -> 42", JSON, :load, "42", proc { |a| a }, { alllow_nan: true }
   end
 
   def test_load_file
@@ -130,14 +97,6 @@ def test_load_file!
     end
   end
 
-  def test_load_default_options
-    assert_send_type "() -> Hash[untyped, untyped]", JSON, :load_default_options
-  end
-
-  def test_load_default_options_eq
-    assert_send_type "(allow_nan: true) -> Hash[untyped, untyped]", JSON, :load_default_options=, { allow_nan: true }
-  end
-
   def test_parse
     assert_send_type "(String) -> 42", JSON, :parse, "42"
     assert_send_type "(_ToStr) -> 42", JSON, :parse, JsonToStr.new("42")
@@ -163,24 +122,6 @@ def test_pretty_generate
     assert_send_type "(ToJson, indent: String) -> String", JSON, :pretty_generate, ToJson.new, { indent: "\t" }
   end
 
-  def test_pretty_unparse
-    assert_send_type "(ToJson) -> String", JSON, :pretty_unparse, ToJson.new
-    assert_send_type "(ToJson, indent: String) -> String", JSON, :pretty_unparse, ToJson.new, { indent: "\t" }
-  end
-
-  def test_recurse_proc
-    assert_send_type "(Integer) { (Integer) -> void } -> void", JSON, :recurse_proc, 42 do |_i| end
-  end
-
-  def test_restore
-    assert_send_type "(String) -> 42", JSON, :restore, "42"
-    assert_send_type "(_ToStr) -> 42", JSON, :restore, JsonToStr.new("42")
-    assert_send_type "(JsonToReadableIO) -> 42", JSON, :restore, JsonToReadableIO.new
-    assert_send_type "(JsonRead) -> 42", JSON, :restore, JsonRead.new
-    assert_send_type "(String, Proc) -> 42", JSON, :restore, "42", proc { }
-    assert_send_type "(String, Proc, Hash[untyped, untyped]) -> 42", JSON, :restore, "42", proc { }, { alllow_nan: true }
-  end
-
   def test_state
     assert_send_type "() -> singleton(JSON::Ext::Generator::State)", JSON, :state
   end
@@ -188,11 +129,6 @@ def test_state
   def test_state_eq
     assert_send_type "(singleton(JSON::Ext::Generator::State)) -> singleton(JSON::Ext::Generator::State)", JSON, :state=, JSON::Ext::Generator::State
   end
-
-  def test_unparse
-    assert_send_type "(ToJson) -> String", JSON, :unparse, ToJson.new
-    assert_send_type "(ToJson, indent: String) -> String", JSON, :unparse, ToJson.new, { indent: "\t" }
-  end
 end
 
 class JSONInstanceTest < Test::Unit::TestCase
@@ -217,30 +153,11 @@ def test_dump
     assert_send_type "(ToJson, JsonWrite, Integer) -> JsonWrite", MyJSON.new, :dump, ToJson.new, JsonWrite.new, 100
   end
 
-  def test_fast_generate
-    assert_send_type "(ToJson) -> String", MyJSON.new, :fast_generate, ToJson.new
-    assert_send_type "(ToJson, indent: String) -> String", MyJSON.new, :fast_generate, ToJson.new, { indent: "\t" }
-  end
-
-  def test_fast_unparse
-    assert_send_type "(ToJson) -> String", MyJSON.new, :fast_unparse, ToJson.new
-    assert_send_type "(ToJson, indent: String) -> String", MyJSON.new, :fast_unparse, ToJson.new, { indent: "\t" }
-  end
-
   def test_generate
     assert_send_type "(ToJson) -> String", MyJSON.new, :generate, ToJson.new
     assert_send_type "(ToJson, indent: String) -> String", MyJSON.new, :generate, ToJson.new, { indent: "\t" }
   end
 
-  def test_load
-    assert_send_type "(String) -> 42", MyJSON.new, :load, "42"
-    assert_send_type "(_ToStr) -> 42", MyJSON.new, :load, JsonToStr.new("42")
-    assert_send_type "(JsonToReadableIO) -> 42", MyJSON.new, :load, JsonToReadableIO.new
-    assert_send_type "(JsonRead) -> 42", MyJSON.new, :load, JsonRead.new
-    assert_send_type "(String, Proc) -> 42", MyJSON.new, :load, "42", proc { }
-    assert_send_type "(String, Proc, Hash[untyped, untyped]) -> 42", MyJSON.new, :load, "42", proc { }, { alllow_nan: true }
-  end
-
   def test_parse
     assert_send_type "(String) -> 42", MyJSON.new, :parse, "42"
     assert_send_type "(_ToStr) -> 42", MyJSON.new, :parse, JsonToStr.new("42")
@@ -258,29 +175,6 @@ def test_pretty_generate
     assert_send_type "(ToJson, indent: String) -> String", MyJSON.new, :pretty_generate, ToJson.new, { indent: "\t" }
   end
 
-  def test_pretty_unparse
-    assert_send_type "(ToJson) -> String", MyJSON.new, :pretty_unparse, ToJson.new
-    assert_send_type "(ToJson, indent: String) -> String", MyJSON.new, :pretty_unparse, ToJson.new, { indent: "\t" }
-  end
-
-  def test_recurse_proc
-    assert_send_type "(Integer) { (Integer) -> void } -> void", MyJSON.new, :recurse_proc, 42 do |_i| end
-  end
-
-  def test_restore
-    assert_send_type "(String) -> 42", MyJSON.new, :restore, "42"
-    assert_send_type "(_ToStr) -> 42", MyJSON.new, :restore, JsonToStr.new("42")
-    assert_send_type "(JsonToReadableIO) -> 42", MyJSON.new, :restore, JsonToReadableIO.new
-    assert_send_type "(JsonRead) -> 42", MyJSON.new, :restore, JsonRead.new
-    assert_send_type "(String, Proc) -> 42", MyJSON.new, :restore, "42", proc { }
-    assert_send_type "(String, Proc, Hash[untyped, untyped]) -> 42", MyJSON.new, :restore, "42", proc { }, { alllow_nan: true }
-  end
-
-  def test_unparse
-    assert_send_type "(ToJson) -> String", MyJSON.new, :unparse, ToJson.new
-    assert_send_type "(ToJson, indent: String) -> String", MyJSON.new, :unparse, ToJson.new, { indent: "\t" }
-  end
-
   def test_to_json_with_object
     assert_send_type "() -> String", Object.new, :to_json
     assert_send_type "(JSON::State) -> String",  Object.new, :to_json, JSON::State.new