diff --git a/src/keys.ts b/src/keys.ts
index bfb290d..4d62593 100644
--- a/src/keys.ts
+++ b/src/keys.ts
@@ -1 +1,3 @@
-export const ListBoxInjectionKey = Symbol()
+import type { InjectionKey } from 'vue'
+
+export const ListBoxInjectionKey = Symbol() as InjectionKey<string>