diff --git a/src/runtime/action/index.ts b/src/runtime/action/index.ts
index 0c440e30a1..a672bb7ae5 100644
--- a/src/runtime/action/index.ts
+++ b/src/runtime/action/index.ts
@@ -55,7 +55,7 @@ export interface ActionReturn<Parameter = never, Attributes extends Record<strin
  * Docs: https://svelte.dev/docs#template-syntax-element-directives-use-action
  */
 export interface Action<Element = HTMLElement, Parameter = never, Attributes extends Record<string, any> = Record<never, any>> {
-	<Node extends Element>(...args: [Parameter] extends [never] ? [node: Node] : undefined extends Parameter? [node: Node, parameter?: Parameter] : [node: Node, parameter: Parameter]): void | ActionReturn<Parameter, Attributes>;
+	<Node extends Element>(...args: [Parameter] extends [never] ? [node: Node] : undefined extends Parameter ? [node: Node, parameter?: Parameter] : [node: Node, parameter: Parameter]): void | ActionReturn<Parameter, Attributes>;
 }
 
 // Implementation notes: