diff --git a/js/util_worker_tasks.js b/js/util_worker_tasks.js
index b084e7b1a..90fa017cd 100644
--- a/js/util_worker_tasks.js
+++ b/js/util_worker_tasks.js
@@ -46,7 +46,6 @@ function calcPoW(
   ttl,
   pubKey,
   data,
-  development,
   difficulty = undefined,
   increment = 1,
   startNonce = 0
@@ -56,7 +55,6 @@ function calcPoW(
     ttl,
     pubKey,
     data,
-    development,
     difficulty,
     increment,
     startNonce
diff --git a/libloki/proof-of-work.js b/libloki/proof-of-work.js
index b1359d4e5..c6a3a4b1e 100644
--- a/libloki/proof-of-work.js
+++ b/libloki/proof-of-work.js
@@ -77,9 +77,7 @@ const pow = {
 
     let nonce = new Uint8Array(NONCE_LEN);
     nonce = pow.incrementNonce(nonce, startNonce); // initial value
-    let trialValue = pow.bigIntToUint8Array(
-      JSBI.BigInt(Number.MAX_SAFE_INTEGER)
-    );
+    let trialValue = new Uint8Array([255, 255, 255, 255, 255, 255, 255, 255]);
     const initialHash = new Uint8Array(
       await crypto.subtle.digest('SHA-512', payload)
     );