diff --git a/packages/svelte/src/compiler/parse/acorn-types.d.ts b/packages/svelte/src/compiler/parse/acorn-types.d.ts
new file mode 100644
index 0000000000..d26761471f
--- /dev/null
+++ b/packages/svelte/src/compiler/parse/acorn-types.d.ts
@@ -0,0 +1,4 @@
+declare module 'acorn' {
+	export function isIdentifierStart(code: number, astral: boolean): boolean;
+	export function isIdentifierChar(code: number, astral: boolean): boolean;
+}