diff --git a/packages/relayer/src/RestRelayer.ts b/packages/relayer/src/RestRelayer.ts
index 0a5b61a6b..e72c18da6 100644
--- a/packages/relayer/src/RestRelayer.ts
+++ b/packages/relayer/src/RestRelayer.ts
@@ -142,7 +142,7 @@ export class RestRelayer implements IRelayer {
               address: address
             },
             refundInfo: {
-              tokenGasPrice: signedTx.tx.gasPrice,
+              tokenGasPrice: signedTx.tx.gasPrice.toString(),
               gasToken: signedTx.tx.gasToken
             }
           }