diff --git a/src/swap/components/Swap.tsx b/src/swap/components/Swap.tsx
index cb5e941..26cbbaa 100644
--- a/src/swap/components/Swap.tsx
+++ b/src/swap/components/Swap.tsx
@@ -257,7 +257,14 @@ function TokenName({ mint }: { mint: PublicKey }) {
 
 function SwapButton() {
   const styles = useStyles();
-  const { fromMint, toMint, fromAmount, toAmount, slippage } = useSwapContext();
+  const {
+    fromMint,
+    toMint,
+    fromAmount,
+    toAmount,
+    slippage,
+    isClosingNewAccounts,
+  } = useSwapContext();
   const { swapClient } = useDexContext();
   const fromMintInfo = useMint(fromMint);
   const toMintInfo = useMint(toMint);
@@ -271,9 +278,9 @@ function SwapButton() {
       throw new Error("Unable to calculate mint decimals");
     }
     const amount = new BN(fromAmount).muln(10 ** fromMintInfo.decimals);
-    const minExpectedSwapAmount = new BN(
-      (toAmount * (100 - slippage)) / 100
-    ).muln(10 ** toMintInfo.decimals);
+    const minExpectedSwapAmount = new BN(toAmount * 10 ** toMintInfo.decimals)
+      .muln(100 - slippage)
+      .divn(100);
     const fromOpenOrders = fromMarket
       ? openOrders.get(fromMarket?.address.toString())
       : undefined;
@@ -291,6 +298,8 @@ function SwapButton() {
       toMarket,
       fromOpenOrders: fromOpenOrders ? fromOpenOrders[0].address : undefined,
       toOpenOrders: toOpenOrders ? toOpenOrders[0].address : undefined,
+      // Auto close newly created open orders accounts.
+      close: isClosingNewAccounts,
     });
   };
   return (
diff --git a/src/swap/components/context/Swap.tsx b/src/swap/components/context/Swap.tsx
index 995c4ec..7af7b51 100644
--- a/src/swap/components/context/Swap.tsx
+++ b/src/swap/components/context/Swap.tsx
@@ -1,4 +1,5 @@
 import React, { useContext, useState } from "react";
+import * as assert from "assert";
 import { PublicKey } from "@solana/web3.js";
 import { SRM_MINT, USDC_MINT } from "../../utils/pubkeys";
 import { useFairRoute } from "./Dex";
@@ -54,6 +55,8 @@ export function SwapContextProvider(props: any) {
   const [fairOverride, setFairOverride] = useState<number | null>(null);
   const fair = _useSwapFair(fromMint, toMint, fairOverride);
 
+  assert.ok(slippage >= 0);
+
   const swapToFromMints = () => {
     const oldFrom = fromMint;
     const oldFromAmount = fromAmount;