diff --git a/lib/zapAggregation.ts b/lib/zapAggregation.ts
index 84669a9..7a3ded4 100644
--- a/lib/zapAggregation.ts
+++ b/lib/zapAggregation.ts
@@ -85,7 +85,8 @@ function collectZap(
     sub.on('eose', () => done())
     setTimeout(() => done(), timeout).unref?.()
     if (typeof (sub as unknown as { on?: unknown }).on === 'function') {
-      ;(sub as any).on('error', onError)
+      const subWithError = sub as unknown as { on: (event: string, handler: (error: Error) => void) => void }
+      subWithError.on('error', onError)
     }
   })
 }