2 files changed, 7 insertions, 3 deletions
diff --git a/packages/utils/src/abi_decoder.ts b/packages/utils/src/abi_decoder.ts
index 150f74a15..d329f917a 100644
--- a/packages/utils/src/abi_decoder.ts
+++ b/packages/utils/src/abi_decoder.ts
@@ -17,7 +17,7 @@ import { BigNumber } from './configured_bignumber';
 export class AbiDecoder {
     private _savedABIs: AbiDefinition[] = [];
     private _methodIds: { [signatureHash: string]: EventAbi } = {};
-    private static _padZeros(address: string) {
+    private static _padZeros(address: string): string {
         let formatted = address;
         if (_.startsWith(formatted, '0x')) {
             formatted = formatted.slice(2);
diff --git a/packages/utils/src/interval_utils.ts b/packages/utils/src/interval_utils.ts
index ebecc7015..6984bf42d 100644
--- a/packages/utils/src/interval_utils.ts
+++ b/packages/utils/src/interval_utils.ts
@@ -1,7 +1,11 @@
 import * as _ from 'lodash';
 
 export const intervalUtils = {
-    setAsyncExcludingInterval(fn: () => Promise<void>, intervalMs: number, onError: (err: Error) => void) {
+    setAsyncExcludingInterval(
+        fn: () => Promise<void>,
+        intervalMs: number,
+        onError: (err: Error) => void,
+    ): NodeJS.Timer {
         let locked = false;
         const intervalId = setInterval(async () => {
             if (locked) {
@@ -21,7 +25,7 @@ export const intervalUtils = {
     clearAsyncExcludingInterval(intervalId: NodeJS.Timer): void {
         clearInterval(intervalId);
     },
-    setInterval(fn: () => void, intervalMs: number, onError: (err: Error) => void) {
+    setInterval(fn: () => void, intervalMs: number, onError: (err: Error) => void): NodeJS.Timer {
         const intervalId = setInterval(() => {
             try {
                 fn();