diff --git a/plugins/css_bundler/src/helpers.ts b/plugins/css_bundler/src/helpers.ts
index 808139d..070728a 100644
--- a/plugins/css_bundler/src/helpers.ts
+++ b/plugins/css_bundler/src/helpers.ts
@@ -25,4 +25,4 @@ export async function hashFile(file: ArrayBuffer): Promise<string> {
 	return [...hash].map((value) => value.toString(16).padStart(2, '0')).join('')
 }
 
-export const cssImports = new Map()
+export const cssImports: Map<string, string> = new Map()