diff --git a/packages/dom-ready/README.md b/packages/dom-ready/README.md
index 6b9ea8ea5ab20e..f3f19529152870 100644
--- a/packages/dom-ready/README.md
+++ b/packages/dom-ready/README.md
@@ -32,11 +32,7 @@ domReady( function () {
 
 _Parameters_
 
--   _callback_ `Callback`: A function to execute after the DOM is ready.
-
-_Returns_
-
--   `void`:
+-   _callback_ `VoidFunction`: A function to execute after the DOM is ready.
 
 <!-- END TOKEN(Autogenerated API docs) -->
 
diff --git a/packages/dom-ready/src/index.js b/packages/dom-ready/src/index.ts
similarity index 55%
rename from packages/dom-ready/src/index.js
rename to packages/dom-ready/src/index.ts
index 6f187a6b3e8444..29d6d81a6b0319 100644
--- a/packages/dom-ready/src/index.js
+++ b/packages/dom-ready/src/index.ts
@@ -1,21 +1,7 @@
-/**
- * @typedef {() => void} Callback
- *
- * TODO: Remove this typedef and inline `() => void` type.
- *
- * This typedef is used so that a descriptive type is provided in our
- * automatically generated documentation.
- *
- * An in-line type `() => void` would be preferable, but the generated
- * documentation is `null` in that case.
- *
- * @see https://github.com/WordPress/gutenberg/issues/18045
- */
-
 /**
  * Specify a function to execute when the DOM is fully loaded.
  *
- * @param {Callback} callback A function to execute after the DOM is ready.
+ * @param callback A function to execute after the DOM is ready.
  *
  * @example
  * ```js
@@ -25,10 +11,8 @@
  * 	//do something after DOM loads.
  * } );
  * ```
- *
- * @return {void}
  */
-export default function domReady( callback ) {
+export default function domReady( callback: VoidFunction ) {
 	if ( typeof document === 'undefined' ) {
 		return;
 	}
diff --git a/packages/dom-ready/src/test/index.test.js b/packages/dom-ready/src/test/index.test.ts
similarity index 88%
rename from packages/dom-ready/src/test/index.test.js
rename to packages/dom-ready/src/test/index.test.ts
index dc1fcb882fc4f2..8020d855e0244c 100644
--- a/packages/dom-ready/src/test/index.test.js
+++ b/packages/dom-ready/src/test/index.test.ts
@@ -14,6 +14,7 @@ describe( 'domReady', () => {
 	describe( 'when document readystate is complete', () => {
 		it( 'should call the callback.', () => {
 			const callback = jest.fn( () => {} );
+			// @ts-expect-error document.readyState is read-only
 			document.readyState = 'complete';
 			domReady( callback );
 			expect( callback ).toHaveBeenCalled();
@@ -23,6 +24,7 @@ describe( 'domReady', () => {
 	describe( 'when document readystate is interactive', () => {
 		it( 'should call the callback.', () => {
 			const callback = jest.fn( () => {} );
+			// @ts-expect-error document.readyState is read-only
 			document.readyState = 'interactive';
 			domReady( callback );
 			expect( callback ).toHaveBeenCalled();
@@ -32,6 +34,7 @@ describe( 'domReady', () => {
 	describe( 'when document readystate is still loading', () => {
 		it( 'should add the callback as an event listener to the DOMContentLoaded event.', () => {
 			const addEventListener = jest.fn( () => {} );
+			// @ts-expect-error document.readyState is read-only
 			document.readyState = 'loading';
 			Object.defineProperty( document, 'addEventListener', {
 				value: addEventListener,