diff --git a/.changeset/curvy-carrots-prove.md b/.changeset/curvy-carrots-prove.md
new file mode 100644
index 000000000000..77239901790d
--- /dev/null
+++ b/.changeset/curvy-carrots-prove.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: account for mounting when `select_option` in `attribute_effect`
diff --git a/packages/svelte/src/internal/client/dom/elements/attributes.js b/packages/svelte/src/internal/client/dom/elements/attributes.js
index 5db685cf3e90..c96338778f44 100644
--- a/packages/svelte/src/internal/client/dom/elements/attributes.js
+++ b/packages/svelte/src/internal/client/dom/elements/attributes.js
@@ -514,9 +514,10 @@ export function attribute_effect(
 
 	if (is_select) {
 		var select = /** @type {HTMLSelectElement} */ (element);
-
+		var mounting = true;
 		effect(() => {
-			select_option(select, /** @type {Record<string | symbol, any>} */ (prev).value);
+			select_option(select, /** @type {Record<string | symbol, any>} */ (prev).value, mounting);
+			mounting = false;
 			init_select(select);
 		});
 	}
diff --git a/packages/svelte/tests/runtime-runes/samples/select-spread-option-selected/_config.js b/packages/svelte/tests/runtime-runes/samples/select-spread-option-selected/_config.js
new file mode 100644
index 000000000000..50da3ac09567
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/select-spread-option-selected/_config.js
@@ -0,0 +1,9 @@
+import { ok, test } from '../../test';
+
+export default test({
+	async test({ assert, target, instance }) {
+		const select = target.querySelector('select');
+		ok(select);
+		assert.equal(select.selectedIndex, 1);
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/select-spread-option-selected/main.svelte b/packages/svelte/tests/runtime-runes/samples/select-spread-option-selected/main.svelte
new file mode 100644
index 000000000000..e5fc6c553538
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/select-spread-option-selected/main.svelte
@@ -0,0 +1,8 @@
+<script>
+	let others = {onclick: ()=> {}}
+</script>
+
+<select {...others}>
+	<option>o1</option>
+	<option selected>o2</option>
+</select>