diff --git a/toLower.js b/toLower.js
deleted file mode 100644
index 1e04555dc..000000000
--- a/toLower.js
+++ /dev/null
@@ -1,26 +0,0 @@
-import toString from './toString.js'
-
-/**
- * Converts `string`, as a whole, to lower case just like
- * [String#toLowerCase](https://mdn.io/toLowerCase).
- *
- * @since 4.0.0
- * @category String
- * @param {string} [string=''] The string to convert.
- * @returns {string} Returns the lower cased string.
- * @example
- *
- * toLower('--Foo-Bar--')
- * // => '--foo-bar--'
- *
- * toLower('fooBar')
- * // => 'foobar'
- *
- * toLower('__FOO_BAR__')
- * // => '__foo_bar__'
- */
-function toLower(value) {
-  return toString(value).toLowerCase()
-}
-
-export default toLower
diff --git a/toUpper.js b/toUpper.js
deleted file mode 100644
index 8ad9b8303..000000000
--- a/toUpper.js
+++ /dev/null
@@ -1,26 +0,0 @@
-
-
-/**
- * Converts `string`, as a whole, to upper case just like
- * [String#toUpperCase](https://mdn.io/toUpperCase).
- *
- * @since 4.0.0
- * @category String
- * @param {string} [string=''] The string to convert.
- * @returns {string} Returns the upper cased string.
- * @example
- *
- * toUpper('--foo-bar--')
- * // => '--FOO-BAR--'
- *
- * toUpper('fooBar')
- * // => 'FOOBAR'
- *
- * toUpper('__foo_bar__')
- * // => '__FOO_BAR__'
- */
-function toUpper(value) {
-  return toString(value).toUpperCase()
-}
-
-export default toUpper