diff --git a/packages/runtime-core/src/directives.ts b/packages/runtime-core/src/directives.ts
index b2618c03a66..be10840784b 100644
--- a/packages/runtime-core/src/directives.ts
+++ b/packages/runtime-core/src/directives.ts
@@ -78,7 +78,7 @@ export type DirectiveArguments = Array<
   | [Directive | undefined]
   | [Directive | undefined, any]
   | [Directive | undefined, any, string]
-  | [Directive | undefined, any, string, DirectiveModifiers]
+  | [Directive | undefined, any, string | undefined, DirectiveModifiers]
 >
 
 /**