diff --git a/Gemfile b/Gemfile
index 8fcb1c3..0c794f5 100644
--- a/Gemfile
+++ b/Gemfile
@@ -7,3 +7,4 @@ group :sig do
   gem "rbs"
   gem "rdoc", "<= 6.11"
 end
+gemspec
diff --git a/lib/base64.rb b/lib/base64.rb
index cd2ecc1..9684cf8 100644
--- a/lib/base64.rb
+++ b/lib/base64.rb
@@ -360,4 +360,13 @@ def urlsafe_decode64(str)
     end
     strict_decode64(str)
   end
+
+  class << self
+    alias encode encode64
+    alias decode decode64
+    alias strict_encode strict_encode64
+    alias strict_decode strict_decode64
+    alias urlsafe_encode urlsafe_encode64
+    alias urlsafe_decode urlsafe_decode64
+  end
 end
diff --git a/test/base64/test_base64.rb b/test/base64/test_base64.rb
index ce71604..4ed0ee8 100644
--- a/test/base64/test_base64.rb
+++ b/test/base64/test_base64.rb
@@ -112,4 +112,25 @@ def test_urlsafe_decode64_unpadded
     assert_equal("\0\0\0", Base64.urlsafe_decode64("AAAA"))
     assert_raise(ArgumentError) { Base64.urlsafe_decode64("AA=") }
   end
+
+  def test_aliases
+    assert_equal(Base64.method(:encode), Base64.method(:encode64))
+    assert_equal(Base64.method(:decode), Base64.method(:decode64))
+    assert_equal(Base64.method(:strict_encode), Base64.method(:strict_encode64))
+    assert_equal(Base64.method(:strict_decode), Base64.method(:strict_decode64))
+    assert_equal(Base64.method(:urlsafe_encode), Base64.method(:urlsafe_encode64))
+    assert_equal(Base64.method(:urlsafe_decode), Base64.method(:urlsafe_decode64))
+  end
+
+  class Test
+    include Base64
+    def check(name)
+      respond_to?(name, true)
+    end
+  end
+
+  def test_module_function_test
+    assert_equal(true, Test.new.check(:encode64))
+    assert_equal(false, Test.new.check(:encode))
+  end
 end