diff --git a/src/libs/SessionUtils.js b/src/libs/SessionUtils.ts
similarity index 79%
rename from src/libs/SessionUtils.js
rename to src/libs/SessionUtils.ts
index 7b1fc9f42d25..a916be2e95da 100644
--- a/src/libs/SessionUtils.js
+++ b/src/libs/SessionUtils.ts
@@ -1,16 +1,10 @@
 import Onyx from 'react-native-onyx';
-import _ from 'underscore';
-import lodashGet from 'lodash/get';
 import ONYXKEYS from '../ONYXKEYS';
 
 /**
  * Determine if the transitioning user is logging in as a new user.
- *
- * @param {String} transitionURL
- * @param {String} sessionEmail
- * @returns {Boolean}
  */
-function isLoggingInAsNewUser(transitionURL, sessionEmail) {
+function isLoggingInAsNewUser(transitionURL: string, sessionEmail: string): boolean {
     // The OldDot mobile app does not URL encode the parameters, but OldDot web
     // does. We don't want to deploy OldDot mobile again, so as a work around we
     // compare the session email to both the decoded and raw email from the transition link.
@@ -27,22 +21,22 @@ function isLoggingInAsNewUser(transitionURL, sessionEmail) {
     // Capture the un-encoded text in the email param
     const emailParamRegex = /[?&]email=([^&]*)/g;
     const matches = emailParamRegex.exec(transitionURL);
-    const linkedEmail = lodashGet(matches, 1, null);
+    const linkedEmail = matches?.[1] ?? null;
     return linkedEmail !== sessionEmail;
 }
 
-let loggedInDuringSession;
+let loggedInDuringSession: boolean | undefined;
 
 // To tell if the user logged in during this session we will check the value of session.authToken once when the app's JS inits. When the user logs out
 // we can reset this flag so that it can be updated again.
 Onyx.connect({
     key: ONYXKEYS.SESSION,
     callback: (session) => {
-        if (!_.isUndefined(loggedInDuringSession)) {
+        if (loggedInDuringSession !== undefined) {
             return;
         }
 
-        if (session && session.authToken) {
+        if (session?.authToken) {
             loggedInDuringSession = false;
         } else {
             loggedInDuringSession = true;
@@ -54,9 +48,6 @@ function resetDidUserLogInDuringSession() {
     loggedInDuringSession = undefined;
 }
 
-/**
- * @returns {boolean}
- */
 function didUserLogInDuringSession() {
     return Boolean(loggedInDuringSession);
 }