diff --git a/stdlib/digest/0/digest.rbs b/stdlib/digest/0/digest.rbs
index cd72b513e1..40d4fda0de 100644
--- a/stdlib/digest/0/digest.rbs
+++ b/stdlib/digest/0/digest.rbs
@@ -70,6 +70,10 @@
 # http://csrc.nist.gov/publications/PubsFIPS.html.
 #
 module Digest
+  # <!-- rdoc-file=ext/digest/lib/digest/version.rb -->
+  # The version string
+  #
+  VERSION: String
   # <!--
   #   rdoc-file=ext/digest/bubblebabble/bubblebabble.c
   #   - Digest.bubblebabble(string) -> bubblebabble_string
diff --git a/stdlib/forwardable/0/forwardable.rbs b/stdlib/forwardable/0/forwardable.rbs
index a2b3749602..27e143bc49 100644
--- a/stdlib/forwardable/0/forwardable.rbs
+++ b/stdlib/forwardable/0/forwardable.rbs
@@ -105,6 +105,15 @@ module Forwardable
   #
   FORWARDABLE_VERSION: String
 
+  # <!-- rdoc-file=lib/forwardable.rb -->
+  # ignored
+  #
+  def self.debug: () -> boolish
+  # <!-- rdoc-file=lib/forwardable.rb -->
+  # ignored
+  #
+  def self.debug=: (boolish) -> void
+
   # <!--
   #   rdoc-file=lib/forwardable.rb
   #   - delegate method => accessor
diff --git a/stdlib/random-formatter/0/random-formatter.rbs b/stdlib/random-formatter/0/random-formatter.rbs
index cc0069161e..21d87ab44a 100644
--- a/stdlib/random-formatter/0/random-formatter.rbs
+++ b/stdlib/random-formatter/0/random-formatter.rbs
@@ -275,3 +275,11 @@ module RBS
     end
   end
 end
+
+%a{annotate:rdoc:skip}
+module Random::Formatter
+  # <!-- rdoc-file=lib/random/formatter.rb -->
+  # The default character list for #alphanumeric.
+  #
+  ALPHANUMERIC: Array[String]
+end
diff --git a/stdlib/singleton/0/singleton.rbs b/stdlib/singleton/0/singleton.rbs
index e6bb42d6f3..27dd78d2f4 100644
--- a/stdlib/singleton/0/singleton.rbs
+++ b/stdlib/singleton/0/singleton.rbs
@@ -95,6 +95,8 @@ module Singleton
   #
   VERSION: String
 
+  def self.module_with_class_methods: () -> singleton(Singleton::SingletonClassMethods)
+
   module SingletonInstanceMethods
     def clone: () -> bot
 
diff --git a/stdlib/time/0/manifest.yaml b/stdlib/time/0/manifest.yaml
new file mode 100644
index 0000000000..c873b0d261
--- /dev/null
+++ b/stdlib/time/0/manifest.yaml
@@ -0,0 +1,2 @@
+dependencies:
+  - name: date
diff --git a/stdlib/time/0/time.rbs b/stdlib/time/0/time.rbs
index 325db6f4b9..cc1c981997 100644
--- a/stdlib/time/0/time.rbs
+++ b/stdlib/time/0/time.rbs
@@ -1,5 +1,7 @@
 %a{annotate:rdoc:skip}
 class Time
+  VERSION: String
+
   interface _TimeLike
     def year: () -> Integer
 
diff --git a/stdlib/tsort/0/tsort.rbs b/stdlib/tsort/0/tsort.rbs
index 521f284a9b..f849914c35 100644
--- a/stdlib/tsort/0/tsort.rbs
+++ b/stdlib/tsort/0/tsort.rbs
@@ -114,6 +114,10 @@
 # *SIAM Journal on Computing*, Vol. 1, No. 2, pp. 146-160, June 1972.
 #
 module TSort[N] : TSort::_Sortable[N]
+  # <!-- rdoc-file=lib/tsort.rb -->
+  # The version string.
+  #
+  VERSION: String
   # <!--
   #   rdoc-file=lib/tsort.rb
   #   - each_strongly_connected_component(each_node, each_child) { |nodes| ... }
diff --git a/test/stdlib/Forwardable_test.rb b/test/stdlib/Forwardable_test.rb
index e92e1f1e6e..94aa01b646 100644
--- a/test/stdlib/Forwardable_test.rb
+++ b/test/stdlib/Forwardable_test.rb
@@ -1,6 +1,30 @@
 require_relative "test_helper"
 require "forwardable"
 
+class ForwardableSingletonTest < Test::Unit::TestCase
+  include TestHelper
+
+  library "forwardable"
+  testing "singleton(::Forwardable)"
+
+  def test_constants
+    assert_const_type "String", "Forwardable::VERSION"
+    assert_const_type "String", "Forwardable::FORWARDABLE_VERSION"
+  end
+
+  def test_debug
+    assert_send_type "() -> boolish",
+                     Forwardable, :debug
+  end
+
+  def test_debug_assign
+    assert_send_type "(boolish) -> void",
+                     Forwardable, :debug=, true
+  ensure
+    Forwardable.debug = nil
+  end
+end
+
 class ForwardableTest < Test::Unit::TestCase
   include TestHelper
 
diff --git a/test/stdlib/Random_Formatter_test.rb b/test/stdlib/Random_Formatter_test.rb
index edc9d09239..7ef2072e59 100644
--- a/test/stdlib/Random_Formatter_test.rb
+++ b/test/stdlib/Random_Formatter_test.rb
@@ -7,6 +7,10 @@ class RandomFormatterSingletonTest < Test::Unit::TestCase
   library "random-formatter"
   testing "singleton(::Random)"
 
+  def test_alphanumeric_constant
+    assert_const_type "Array[String]", "Random::Formatter::ALPHANUMERIC"
+  end
+
   def test_base64
     assert_send_type "() -> ::String",
                      Random, :base64
diff --git a/test/stdlib/TSort_test.rb b/test/stdlib/TSort_test.rb
index 277de4ccf1..51770b0358 100644
--- a/test/stdlib/TSort_test.rb
+++ b/test/stdlib/TSort_test.rb
@@ -8,6 +8,10 @@ class TSortSingletonTest < Test::Unit::TestCase
   library 'tsort'
   testing "singleton(::TSort)"
 
+  def test_version
+    assert_const_type "String", "TSort::VERSION"
+  end
+
   class EachNode
     def initialize(*nodes)
       @nodes = nodes
diff --git a/test/stdlib/TimeExtension_test.rb b/test/stdlib/TimeExtension_test.rb
index 590f51724f..4f4e8acc6c 100644
--- a/test/stdlib/TimeExtension_test.rb
+++ b/test/stdlib/TimeExtension_test.rb
@@ -15,6 +15,10 @@ def initialize(mon, day, year)
     end
   end
 
+  def test_version
+    assert_const_type "String", "Time::VERSION"
+  end
+
   def test_zone_offset
     assert_send_type "(String) -> Integer",
                      Time, :zone_offset, "EST"
diff --git a/test/stdlib/digest/Digest_test.rb b/test/stdlib/digest/Digest_test.rb
index 20b1146119..b49560a5f0 100644
--- a/test/stdlib/digest/Digest_test.rb
+++ b/test/stdlib/digest/Digest_test.rb
@@ -9,6 +9,10 @@ class DigestSingletonTest < Test::Unit::TestCase
   testing 'singleton(::Digest)'
 
 
+  def test_version
+    assert_const_type "String", "Digest::VERSION"
+  end
+
   def test_const_missing
     assert_send_type  '(::Symbol name) -> singleton(::Digest::Base)',
                       ::Digest, :const_missing, :SHA1
diff --git a/test/stdlib/singleton_test.rb b/test/stdlib/singleton_test.rb
index 9901e6dadc..8b63e3d016 100644
--- a/test/stdlib/singleton_test.rb
+++ b/test/stdlib/singleton_test.rb
@@ -3,7 +3,7 @@
 
 class SingletonSingletonTest < Test::Unit::TestCase
   include TestHelper
-  
+
   library 'singleton'
   testing 'singleton(::Singleton)'
 
@@ -16,4 +16,13 @@ def test_singleton_instance_methods
 
     assert_const_type "Module", "Singleton::SingletonInstanceMethods"
   end
+
+  def test_version
+    assert_const_type "String", "Singleton::VERSION"
+  end
+
+  def test_module_with_class_methods
+    assert_send_type "() -> singleton(Singleton::SingletonClassMethods)",
+                     Singleton, :module_with_class_methods
+  end
 end