diff --git a/packages/svelte/test/css/samples/preserve-unused-selector/_config.js b/packages/svelte/test/css/samples/preserve-unused-selector/_config.js
new file mode 100644
index 000000000000..8bf5058a9813
--- /dev/null
+++ b/packages/svelte/test/css/samples/preserve-unused-selector/_config.js
@@ -0,0 +1,30 @@
+export default {
+	compileOptions: {
+		preserveUnusedSelectors: true
+	},
+	warnings: [
+		{
+			filename: 'SvelteComponent.svelte',
+			code: 'css-unused-selector',
+			message: 'Unused CSS selector ".bar"',
+			start: {
+				line: 8,
+				column: 1,
+				character: 60
+			},
+			end: {
+				line: 8,
+				column: 5,
+				character: 64
+			},
+			pos: 60,
+			frame: `
+			 6:   }
+			 7:
+			 8:   .bar {
+			      ^
+			 9:     color: blue;
+			10:   }`
+		}
+	]
+};
diff --git a/packages/svelte/test/css/samples/preserve-unused-selector/expected.css b/packages/svelte/test/css/samples/preserve-unused-selector/expected.css
new file mode 100644
index 000000000000..5633dd783fdd
--- /dev/null
+++ b/packages/svelte/test/css/samples/preserve-unused-selector/expected.css
@@ -0,0 +1 @@
+.foo.svelte-xyz{color:red}.bar{color:blue}
\ No newline at end of file
diff --git a/packages/svelte/test/css/samples/preserve-unused-selector/expected.html b/packages/svelte/test/css/samples/preserve-unused-selector/expected.html
new file mode 100644
index 000000000000..cfad41216efe
--- /dev/null
+++ b/packages/svelte/test/css/samples/preserve-unused-selector/expected.html
@@ -0,0 +1 @@
+<div class="foo svelte-xyz"></div>
\ No newline at end of file
diff --git a/packages/svelte/test/css/samples/preserve-unused-selector/input.svelte b/packages/svelte/test/css/samples/preserve-unused-selector/input.svelte
new file mode 100644
index 000000000000..1d62e3a67577
--- /dev/null
+++ b/packages/svelte/test/css/samples/preserve-unused-selector/input.svelte
@@ -0,0 +1,11 @@
+<div class='foo'></div>
+
+<style>
+	.foo {
+		color: red;
+	}
+
+	.bar {
+		color: blue;
+	}
+</style>
\ No newline at end of file