diff --git a/package.json b/package.json
index 6606869..5472b92 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@tornado/tornado-oracles",
-  "version": "1.3.2",
+  "version": "1.4.0",
   "description": "Gas oracle for Tornado-specific transactions",
   "main": "./lib/index.js",
   "types": "./lib/index.d.ts",
diff --git a/src/feeOracle.ts b/src/feeOracle.ts
index 6e04d64..cc41cba 100644
--- a/src/feeOracle.ts
+++ b/src/feeOracle.ts
@@ -125,7 +125,7 @@ export abstract class TornadoFeeOracle implements ITornadoFeeOracle {
   async getGasPrice(
     type: TxType = 'other',
     speed: LegacyGasPriceKey = 'fast',
-    bumpPercent: number = 0,
+    bumpPercent?: number,
   ): Promise<HexadecimalStringifiedNumber> {
     const gasPriceParams = await this.getGasPriceParams(type, speed, bumpPercent);
     return calculateGasPriceInWei(gasPriceParams).toHexString();