diff --git a/lib/mime.ts b/lib/mime.ts
index a8e7cf4..a457721 100644
--- a/lib/mime.ts
+++ b/lib/mime.ts
@@ -25,7 +25,7 @@ export class MimeInfo {
   }
 }
 
-export const MimeDB = new class {
+export const MimeDB = new class MimeDB {
   private readonly mimeToExts: Map<string, MimeInfo>;
 
   private readonly registeredExtensions: Set<string>;