diff --git a/packages/ethash/src/index.ts b/packages/ethash/src/index.ts
index 48e928a4bf..a4c311e640 100644
--- a/packages/ethash/src/index.ts
+++ b/packages/ethash/src/index.ts
@@ -240,6 +240,8 @@ export default class Ethash {
                 resolve()
               }
             })
+          }).catch(function (e) {
+            cb(e)
           })
         }
         if (!error) {