diff --git a/lib/kangaru/inflectors/constant_inflector.rb b/lib/kangaru/inflectors/constant_inflector.rb
new file mode 100644
index 0000000..c9ec8b1
--- /dev/null
+++ b/lib/kangaru/inflectors/constant_inflector.rb
@@ -0,0 +1,13 @@
+module Kangaru
+  module Inflectors
+    class ConstantInflector < ClassInflector
+      LAST_WORD = /(::)?(?!.*::)(.*)$/
+
+      def inflect
+        super.gsub(LAST_WORD) do |last_word|
+          ScreamingSnakecaseInflector.inflect(last_word)
+        end
+      end
+    end
+  end
+end
diff --git a/sig/kangaru/inflectors/constant_inflector.rbs b/sig/kangaru/inflectors/constant_inflector.rbs
new file mode 100644
index 0000000..921d79b
--- /dev/null
+++ b/sig/kangaru/inflectors/constant_inflector.rbs
@@ -0,0 +1,7 @@
+module Kangaru
+  module Inflectors
+    class ConstantInflector < ClassInflector
+      LAST_WORD: Regexp
+    end
+  end
+end
diff --git a/spec/kangaru/inflectors/constant_inflector_spec.rb b/spec/kangaru/inflectors/constant_inflector_spec.rb
new file mode 100644
index 0000000..c4d456a
--- /dev/null
+++ b/spec/kangaru/inflectors/constant_inflector_spec.rb
@@ -0,0 +1,42 @@
+RSpec.describe Kangaru::Inflectors::ConstantInflector do
+  subject(:inflector) { described_class.new(string) }
+
+  describe "#inflect" do
+    subject(:inflection) { inflector.inflect }
+
+    include_examples :runs_inflections, [
+      { from: "foo_bar_baz",     to: "FOO_BAR_BAZ" },
+      { from: "foo_bar__baz",    to: "FOO_BAR_BAZ" },
+      { from: "foo__bar_baz",    to: "FOO_BAR_BAZ" },
+      { from: "foo__bar__baz",   to: "FOO_BAR_BAZ" },
+
+      { from: "foo-bar-baz",     to: "FOO_BAR_BAZ" },
+      { from: "foo--bar--baz",   to: "FOO_BAR_BAZ" },
+      { from: "foo-bar--baz",    to: "FOO_BAR_BAZ" },
+      { from: "foo--bar-baz",    to: "FOO_BAR_BAZ" },
+
+      { from: "fooBarBaz",       to: "FOO_BAR_BAZ" },
+      { from: "FooBarBaz",       to: "FOO_BAR_BAZ" },
+      { from: "FOOBARBAZ",       to: "FOOBARBAZ" },
+      { from: "FOO_BAR_BAZ",     to: "FOO_BAR_BAZ" },
+
+      { from: "Foo::Bar::Baz",   to: "Foo::Bar::BAZ" },
+      { from: "Foo::BarBaz",     to: "Foo::BAR_BAZ" },
+      { from: "FooBar::Baz",     to: "FooBar::BAZ" },
+
+      { from: "::FOOBARBAZ",     to: "::FOOBARBAZ" },
+      { from: "::Foo::Bar::Baz", to: "::Foo::Bar::BAZ" },
+      { from: "::Foo::BarBaz",   to: "::Foo::BAR_BAZ" },
+      { from: "::FooBar::Baz",   to: "::FooBar::BAZ" },
+      { from: "::FooBarBaz",     to: "::FOO_BAR_BAZ" },
+      { from: "::FOO_BAR_BAZ",   to: "::FOO_BAR_BAZ" },
+
+      { from: "foo_bar_baz.rb",  to: "FOO_BAR_BAZ" },
+      { from: "foo/bar/baz.rb",  to: "Foo::Bar::BAZ" },
+      { from: "foo/barBaz.rb",   to: "Foo::BAR_BAZ" },
+      { from: "/foo_bar_baz.rb", to: "::FOO_BAR_BAZ" },
+      { from: "/foo/bar/baz.rb", to: "::Foo::Bar::BAZ" },
+      { from: "/foo/barBaz.rb",  to: "::Foo::BAR_BAZ" }
+    ]
+  end
+end