diff --git a/__tests__/hardhat-utils.js b/__tests__/hardhat-utils.js
index 9f5055c7ae5..0ba150ed7e2 100644
--- a/__tests__/hardhat-utils.js
+++ b/__tests__/hardhat-utils.js
@@ -43,7 +43,11 @@ export const setupDAI = async () => {
     FIXTURE_WEB3_ADDRESS,
     '100000000000000000000'
   );
-  const sent = await signer.sendTransaction(tx);
+  const sent = await signer.sendTransaction({
+    ...tx,
+    maxFeePerGas: '0xe8990a4600',
+    maxPriorityFeePerGas: '0xe8990a4600'
+  });
 
   await sent.wait();
 
diff --git a/src/services/ApiService/Gas/eip1559.test.ts b/src/services/ApiService/Gas/eip1559.test.ts
index a33254fd88d..6862924e4e4 100644
--- a/src/services/ApiService/Gas/eip1559.test.ts
+++ b/src/services/ApiService/Gas/eip1559.test.ts
@@ -88,6 +88,20 @@ describe('estimateFees', () => {
     });
   });
 
+  it('uses 1.6 multiplier for base if above 40 gwei', async () => {
+    (mockProvider.getLatestBlock as jest.MockedFunction<
+      typeof mockProvider.getLatestBlock
+    >).mockResolvedValueOnce({ ...block, baseFeePerGas: BigNumber.from('0x11766ffa76') });
+    (mockProvider.getFeeHistory as jest.MockedFunction<
+      typeof mockProvider.getFeeHistory
+    >).mockResolvedValueOnce(feeHistory);
+    return expect(estimateFees(mockProvider)).resolves.toStrictEqual({
+      baseFee: bigify('75001494134'),
+      maxFeePerGas: bigify('120000000000'),
+      maxPriorityFeePerGas: bigify('3000000000')
+    });
+  });
+
   it('uses 1.4 multiplier for base if above 100 gwei', async () => {
     (mockProvider.getLatestBlock as jest.MockedFunction<
       typeof mockProvider.getLatestBlock
diff --git a/src/services/ApiService/Gas/eip1559.ts b/src/services/ApiService/Gas/eip1559.ts
index d564dd9162c..7d1bad37800 100644
--- a/src/services/ApiService/Gas/eip1559.ts
+++ b/src/services/ApiService/Gas/eip1559.ts
@@ -21,7 +21,7 @@ export const FALLBACK_ESTIMATE = {
 const PRIORITY_FEE_INCREASE_BOUNDARY = 200; // %
 
 const roundToWholeGwei = (wei: BigNumber) => {
-  const gwei = bigify(fromWei(wei, 'gwei'));
+  const gwei = bigify(fromWei(wei.integerValue(), 'gwei'));
   const rounded = gwei.integerValue(BigNumber.ROUND_HALF_UP);
   return bigify(toWei(rounded.toString(10), getDecimalFromEtherUnit('gwei')));
 };