diff --git a/core/float.rbs b/core/float.rbs
index 057d928..44d4481 100644
--- a/core/float.rbs
+++ b/core/float.rbs
@@ -13,10 +13,6 @@ class Float < Object
 
   def **: (Integer | Float) -> Float
 
-  def ==: (untyped other) -> bool
-
-  def !=: (untyped other) -> bool
-
   def <: (Integer | Float other) -> bool
 
   def <=: (Integer | Float other) -> bool
diff --git a/core/integer.rbs b/core/integer.rbs
index 5e96f19..ecfe803 100644
--- a/core/integer.rbs
+++ b/core/integer.rbs
@@ -34,10 +34,6 @@ class Integer < Object
 
   def >>: (Integer) -> Integer
 
-  def ==: (untyped other) -> bool
-
-  def !=: (untyped other) -> bool
-
   def <: (Integer | Float other) -> bool
 
   def <=: (Integer | Float other) -> bool
diff --git a/core/object.rbs b/core/object.rbs
index 7a8c495..f0a8776 100644
--- a/core/object.rbs
+++ b/core/object.rbs
@@ -1,2 +1,92 @@
 class Object < BasicObject
+  def !: () -> bool
+  def self.!: () -> bool
+
+  def !=: (untyped other) -> bool
+  def self.!=: (untyped other) -> bool
+
+  def <=>: (untyped other) -> bool
+  def self.<=>: (untyped other) -> bool
+
+  def ==: (untyped other) -> bool
+  def self.==: (untyped other) -> bool
+
+  def ===: (untyped other) -> bool
+  def self.===: (untyped other) -> bool
+
+  def <: (untyped other) -> bool
+
+  def <=: (untyped other) -> bool
+
+  def >: (untyped other) -> bool
+
+  def >=: (untyped other) -> bool
+
+  def class: () -> class
+  def self.class: () -> self
+
+  def dup: () -> self
+  def self.dup: () -> self
+
+  def block_given?: () -> bool
+
+  # TODO: Module
+  def kind_of?: (Class) -> bool
+  def self.kind_of?: (Class) -> bool
+
+  alias is_a? kind_of?
+  alias self.is_a? self.kind_of?
+
+  def nil?: () -> bool
+  def self.nil?: () -> bool
+
+  # TODO: Array
+  def p: () -> nil
+       | [T](T arg0) -> T
+
+  def print: (*untyped args) -> nil
+
+  def puts: (*untyped args) -> nil
+
+  # TODO Exception
+  def raise: () -> bot
+           | (String message) -> bot
+  #        | (Exception) -> bot
+  #        | (singleton(Exception)) -> bot
+  #        | (Exception, String message) -> bot
+  #        | (singleton(Exception), String message) -> bot
+
+  # TODO: Symbol
+  # def self.attr_reader: (*String names) -> void
+
+  # TODO: Symbol
+  # def self.attr_accessor: (*Symbol names) -> void
+
+  # TODO: Module
+  # def include: (*Module mods) -> void
+  # def self.include: (*Module mods) -> void
+  #
+  # alias extend include
+  # alias self.extend include
+
+  # TODO: Array, Symbol
+  # def self.constants: (?bool inherit) -> Array[Symbol]
+
+  def self.public: () -> void
+
+  def self.private: () -> void
+
+  def self.protected: () -> void
+
+  def sprintf: (String format, *untyped args) -> String
+
+  def printf: (String format, *untyped args) -> nil
+
+  def to_s: () -> String
+  def self.to_s: () -> String
+
+  alias inspect to_s
+  alias self.inspect self.to_s
+
+  def loop: () { () -> void } -> bot
 end
diff --git a/core/string.rbs b/core/string.rbs
index fadf996..1abbd72 100644
--- a/core/string.rbs
+++ b/core/string.rbs
@@ -1,10 +1,6 @@
 class String < Object
   def initialize: (?String source) -> void
 
-  def ==: (untyped other) -> bool
-
-  def !=: (untyped other) -> bool
-
   def <: (String other) -> bool
 
   def <=: (String other) -> bool
diff --git a/test/object.rb b/test/object.rb
index 8e9b8f9..2a828a3 100644
--- a/test/object.rb
+++ b/test/object.rb
@@ -1 +1,95 @@
 # frozen_string_literal: true
+
+# rubocop:disable Lint/Void
+# rubocop:disable Lint/UnreachableCode
+# rubocop:disable Lint/UselessAccessModifier
+# rubocop:disable Style/CaseEquality
+# rubocop:disable Style/ClassCheck
+# rubocop:disable Style/FormatString
+# rubocop:disable Style/RedundantFormat
+
+object = Object.new
+
+!object
+!Object
+
+object != true
+Object != true
+
+object <=> true
+Object <=> true
+
+object == true
+Object == true
+
+object === true
+Object === true
+
+object < 1
+
+object <= 1
+
+object > 1
+
+object >= 1
+
+object.class
+Object.class
+
+object.dup
+Object.dup
+
+block_given?
+object.block_given?
+
+object.kind_of? Object
+Object.kind_of? Object
+
+object.is_a? Object
+Object.is_a? Object
+
+object.nil?
+Object.nil?
+
+p
+p 1
+object.p
+object.p 1
+
+print
+print 1, true, 'a'
+object.print
+object.print 1, true, 'a'
+
+puts
+puts 1, true, 'a'
+object.puts
+object.puts 1, true, 'a'
+
+raise
+raise 'error'
+object.raise
+object.raise 'error'
+
+# @type const A: A
+class A
+  public
+
+  private
+
+  protected
+end
+
+sprintf "%d\n", 123
+
+printf "%d\n", 123
+
+object.to_s
+Object.to_s
+
+object.inspect
+Object.inspect
+
+loop { puts }
+
+# rubocop:enable all