diff --git a/src/util/warcwriter.ts b/src/util/warcwriter.ts
index ddf79d37..54012e6c 100644
--- a/src/util/warcwriter.ts
+++ b/src/util/warcwriter.ts
@@ -86,7 +86,7 @@ export class WARCWriter implements IndexerOffsetLength {
       this.filename = this._initNewFile();
     }
 
-    let fh: Writable | null = this.fh;
+    let fh = this.fh;
 
     if (!fh) {
       fh = fs.createWriteStream(path.join(this.archivesDir, this.filename));