diff --git a/src/shared/utils/transaction/simulate-queued-transaction.ts b/src/shared/utils/transaction/simulate-queued-transaction.ts
index 4cdc6c85..fde34995 100644
--- a/src/shared/utils/transaction/simulate-queued-transaction.ts
+++ b/src/shared/utils/transaction/simulate-queued-transaction.ts
@@ -64,7 +64,7 @@ export const doSimulateTransaction = async (
     });
 
     if (transaction.transactionMode === "sponsored") {
-      if (!isZkSyncChain(chain)) {
+      if (!(await isZkSyncChain(chain))) {
         throw new Error(
           "Sponsored EOA transactions are only supported on zkSync chains.",
         );
diff --git a/src/worker/tasks/send-transaction-worker.ts b/src/worker/tasks/send-transaction-worker.ts
index 21ce190b..d109cb24 100644
--- a/src/worker/tasks/send-transaction-worker.ts
+++ b/src/worker/tasks/send-transaction-worker.ts
@@ -290,7 +290,7 @@ const _sendTransaction = async (
   let account: Account;
 
   if (queuedTransaction.transactionMode === "sponsored") {
-    if (!isZkSyncChain(chain)) {
+    if (!(await isZkSyncChain(chain))) {
       job.log(
         "Sponsored EOA transactions are only supported on zkSync chains.",
       );