diff --git a/src/containers/OnBoarding/ModifySafe.tsx b/src/containers/OnBoarding/ModifySafe.tsx
index ea0977b7..ef46984f 100644
--- a/src/containers/OnBoarding/ModifySafe.tsx
+++ b/src/containers/OnBoarding/ModifySafe.tsx
@@ -1,4 +1,4 @@
-import { ethers } from 'ethers'
+import { BigNumber, ethers } from 'ethers'
 import React, { useCallback, useMemo, useState } from 'react'
 import styled from 'styled-components'
 import Button from '../../components/Button'
@@ -90,20 +90,25 @@ const ModifySafe = ({
             onLeftInput(availableEth as string)
         }
     }
+
     const onMaxRightInput = () => {
         if (isDeposit) {
             onRightInput(availableRai.toString())
         } else {
             const availableRaiBN = ethers.utils.parseEther(availableRai)
 
-            const raiBalanceBN = ethers.utils.parseEther(
-                balances.rai.toString()
-            )
+            const raiBalanceBN = balances.rai
+                ? ethers.utils.parseEther(balances.rai.toString())
+                : BigNumber.from('0')
 
             const isMore = raiBalanceBN.gt(availableRaiBN)
 
             onRightInput(
-                isMore ? availableRai.toString() : balances.rai.toString()
+                isMore
+                    ? availableRai.toString()
+                    : balances.rai
+                    ? balances.rai.toString()
+                    : '0'
             )
         }
     }
diff --git a/src/hooks/useSafe.ts b/src/hooks/useSafe.ts
index d3b3633a..f3006cac 100644
--- a/src/hooks/useSafe.ts
+++ b/src/hooks/useSafe.ts
@@ -9,6 +9,7 @@ import {
     getLiquidationPrice,
     getRatePercentage,
     returnAvaiableDebt,
+    returnPercentAmount,
     returnTotalDebt,
     returnTotalValue,
     safeIsSafe,
@@ -261,6 +262,22 @@ export function useSafeInfo(type: SafeTypes = 'create') {
             error = error ?? `RAI to repay cannot exceed owed amount`
         }
 
+        if (!rightInputBN.isZero()) {
+            const repayPercent = returnPercentAmount(
+                rightInput,
+                availableRai as string
+            )
+
+            if (
+                rightInputBN.lt(BigNumber.from(availableRaiBN)) &&
+                repayPercent > 95
+            ) {
+                error =
+                    error ??
+                    `You can only repay a minimum of ${availableRai} RAI to avoid leaving residual values`
+            }
+        }
+
         if (!rightInputBN.isZero() && rightInputBN.gt(raiBalanceBN)) {
             error = error ?? `balance_issue`
         }