diff --git a/.changeset/cyan-students-unite.md b/.changeset/cyan-students-unite.md
new file mode 100644
index 00000000..6f50e81b
--- /dev/null
+++ b/.changeset/cyan-students-unite.md
@@ -0,0 +1,5 @@
+---
+'preact-render-to-string': patch
+---
+
+Ensures `defaultChecked` is serialized as `checked` attribute
diff --git a/src/index.js b/src/index.js
index f5024e40..7a740a45 100644
--- a/src/index.js
+++ b/src/index.js
@@ -15,7 +15,8 @@ const SHALLOW = { shallow: true };
 // components without names, kept as a hash for later comparison to return consistent UnnamedComponentXX names.
 const UNNAMED = [];
 
-const VOID_ELEMENTS = /^(area|base|br|col|embed|hr|img|input|link|meta|param|source|track|wbr)$/;
+const VOID_ELEMENTS =
+	/^(area|base|br|col|embed|hr|img|input|link|meta|param|source|track|wbr)$/;
 
 const UNSAFE_NAME = /[\s\n\\/='"\0<>]/;
 
@@ -258,10 +259,14 @@ function _renderToString(vnode, context, opts, inner, isSvgMode, selectValue) {
 
 			if (name === 'defaultValue') {
 				name = 'value';
+			} else if (name === 'defaultChecked') {
+				name = 'checked';
+			} else if (name === 'defaultSelected') {
+				name = 'selected';
 			} else if (name === 'className') {
 				if (typeof props.class !== 'undefined') continue;
 				name = 'class';
-			} else if (isSvgMode && name.match(/^xlink:?./)) {
+			} else if (isSvgMode && /^xlink:?./.test(name)) {
 				name = name.toLowerCase().replace(/^xlink:?/, 'xlink:');
 			}
 
diff --git a/test/render.test.js b/test/render.test.js
index 4ef1ce41..fe3e9bf0 100644
--- a/test/render.test.js
+++ b/test/render.test.js
@@ -95,6 +95,20 @@ describe('render', () => {
 			expect(rendered).to.equal(expected);
 		});
 
+		it('should serialize defaultChecked prop to the checked attribute', () => {
+			let rendered = render(<input type="checkbox" defaultChecked />),
+				expected = `<input type="checkbox" checked />`;
+
+			expect(rendered).to.equal(expected);
+		});
+
+		it('should serialize defaultSelected prop to the selected attribute', () => {
+			let rendered = render(<option defaultSelected />),
+				expected = `<option selected></option>`;
+
+			expect(rendered).to.equal(expected);
+		});
+
 		it('should include boolean aria-* attributes', () => {
 			let rendered = render(<div aria-hidden aria-whatever={false} />),
 				expected = `<div aria-hidden="true" aria-whatever="false"></div>`;