diff --git a/test/hydration/index.js b/test/hydration/index.js
index 30647cace1..e356b8670b 100644
--- a/test/hydration/index.js
+++ b/test/hydration/index.js
@@ -14,7 +14,7 @@ let compileOptions = null;
 
 const sveltePath = process.cwd();
 
-describe('hydration', () => {
+describe.only('hydration', () => {
 	before(() => {
 		const svelte = loadSvelte();
 
diff --git a/test/hydration/samples/binding-input/main.svelte b/test/hydration/samples/binding-input/main.svelte
index e521cf7f9e..c26eb9d595 100644
--- a/test/hydration/samples/binding-input/main.svelte
+++ b/test/hydration/samples/binding-input/main.svelte
@@ -1,2 +1,6 @@
+<script>
+	export let name;
+</script>
+
 <input bind:value={name}>
 <p>Hello {name}!</p>
\ No newline at end of file
diff --git a/test/hydration/samples/dynamic-text-changed/main.svelte b/test/hydration/samples/dynamic-text-changed/main.svelte
index 543c6059c4..8532c94ac9 100644
--- a/test/hydration/samples/dynamic-text-changed/main.svelte
+++ b/test/hydration/samples/dynamic-text-changed/main.svelte
@@ -1 +1,5 @@
+<script>
+	export let name;
+</script>
+
 <h1>Hello {name}!</h1>
\ No newline at end of file
diff --git a/test/hydration/samples/dynamic-text/main.svelte b/test/hydration/samples/dynamic-text/main.svelte
index 543c6059c4..8532c94ac9 100644
--- a/test/hydration/samples/dynamic-text/main.svelte
+++ b/test/hydration/samples/dynamic-text/main.svelte
@@ -1 +1,5 @@
+<script>
+	export let name;
+</script>
+
 <h1>Hello {name}!</h1>
\ No newline at end of file
diff --git a/test/hydration/samples/each-block-arg-clash/main.svelte b/test/hydration/samples/each-block-arg-clash/main.svelte
index 7f04cd5e2f..a25f661fc7 100644
--- a/test/hydration/samples/each-block-arg-clash/main.svelte
+++ b/test/hydration/samples/each-block-arg-clash/main.svelte
@@ -1,3 +1,7 @@
+<script>
+	export let things;
+</script>
+
 <ul>
 	{#each things.foo as foo}
 		<li>{foo}</li>
diff --git a/test/hydration/samples/each-block/main.svelte b/test/hydration/samples/each-block/main.svelte
index 6c5973e9a4..a75df5740b 100644
--- a/test/hydration/samples/each-block/main.svelte
+++ b/test/hydration/samples/each-block/main.svelte
@@ -1,3 +1,7 @@
+<script>
+	export let things;
+</script>
+
 <ul>
 	{#each things as thing}
 		<li>{thing}</li>
diff --git a/test/hydration/samples/element-attribute-added/main.svelte b/test/hydration/samples/element-attribute-added/main.svelte
index c47595732e..c33bc0981c 100644
--- a/test/hydration/samples/element-attribute-added/main.svelte
+++ b/test/hydration/samples/element-attribute-added/main.svelte
@@ -1 +1,5 @@
+<script>
+	export let className;
+</script>
+
 <div class={className}></div>
\ No newline at end of file
diff --git a/test/hydration/samples/event-handler/main.svelte b/test/hydration/samples/event-handler/main.svelte
index d51636617f..3d1a05ed3e 100644
--- a/test/hydration/samples/event-handler/main.svelte
+++ b/test/hydration/samples/event-handler/main.svelte
@@ -1,3 +1,7 @@
+<script>
+	let clicked;
+</script>
+
 <button on:click='{() => clicked = true}'>click me</button>
 
 {#if clicked}
diff --git a/test/hydration/samples/if-block-anchor/main.svelte b/test/hydration/samples/if-block-anchor/main.svelte
index 59ea50e259..f52627cdd6 100644
--- a/test/hydration/samples/if-block-anchor/main.svelte
+++ b/test/hydration/samples/if-block-anchor/main.svelte
@@ -1,3 +1,8 @@
+<script>
+	export let foo;
+	export let bar;
+</script>
+
 <div>
 	{#if foo}
 		<p>foo!</p>
diff --git a/test/hydration/samples/if-block-false/main.svelte b/test/hydration/samples/if-block-false/main.svelte
index 5a91401cdb..d2d4e411a0 100644
--- a/test/hydration/samples/if-block-false/main.svelte
+++ b/test/hydration/samples/if-block-false/main.svelte
@@ -1,3 +1,7 @@
+<script>
+	export let foo;
+</script>
+
 <p>before</p>
 {#if foo}
 	<p>foo!</p>
diff --git a/test/hydration/samples/if-block-update/main.svelte b/test/hydration/samples/if-block-update/main.svelte
index b43dab708f..5c22693283 100644
--- a/test/hydration/samples/if-block-update/main.svelte
+++ b/test/hydration/samples/if-block-update/main.svelte
@@ -1,3 +1,8 @@
+<script>
+	export let foo;
+	export let bar;
+</script>
+
 {#if foo}
 	<p>foo!</p>
 {/if}
diff --git a/test/hydration/samples/if-block/main.svelte b/test/hydration/samples/if-block/main.svelte
index e36517e10c..545d81d44a 100644
--- a/test/hydration/samples/if-block/main.svelte
+++ b/test/hydration/samples/if-block/main.svelte
@@ -1,3 +1,7 @@
+<script>
+	export let foo;
+</script>
+
 {#if foo}
 	<p>foo!</p>
 {/if}
\ No newline at end of file