diff --git a/.changeset/old-houses-drum.md b/.changeset/old-houses-drum.md
new file mode 100644
index 0000000000..78f26ee549
--- /dev/null
+++ b/.changeset/old-houses-drum.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: provide `unstate` in server environment
diff --git a/packages/svelte/src/main/main-server.js b/packages/svelte/src/main/main-server.js
index b9f81c5253..844aec50d1 100644
--- a/packages/svelte/src/main/main-server.js
+++ b/packages/svelte/src/main/main-server.js
@@ -20,3 +20,13 @@ export function beforeUpdate() {}
 
 /** @returns {void} */
 export function afterUpdate() {}
+
+/**
+ * @template T
+ * @param {T} value
+ * @returns {T}
+ */
+export function unstate(value) {
+	// There's no signals/proxies on the server, so just return the value
+	return value;
+}