diff --git a/src/export/packer/buffer.ts b/src/export/packer/buffer.ts
index c30fe202e6..9c46c4e166 100644
--- a/src/export/packer/buffer.ts
+++ b/src/export/packer/buffer.ts
@@ -1,8 +1,9 @@
 import { File } from "../../file";
 import { BufferStream } from "./buffer-stream";
 import { Compiler } from "./compiler";
+import { IPacker } from "./packer";
 
-export class BufferPacker {
+export class BufferPacker implements IPacker {
     private readonly packer: Compiler;
 
     constructor(file: File) {