diff --git a/typescript/lambda-greeter/src/app.ts b/typescript/lambda-greeter/src/app.ts
index c7529bde..6c9b0357 100644
--- a/typescript/lambda-greeter/src/app.ts
+++ b/typescript/lambda-greeter/src/app.ts
@@ -19,7 +19,7 @@ const doGreetAndRemember = async (
   ctx: restate.RestateContext,
   name: string
 ) => {
-  let seen = (await ctx.get<number>("seen")) || 0;
+  let seen = (await ctx.get<number>("seen")) ?? 0;
   seen += 1;
 
   ctx.set("seen", seen);
diff --git a/typescript/ticket-reservation/src/ticket_db.ts b/typescript/ticket-reservation/src/ticket_db.ts
index 2076f1e2..22eec96e 100644
--- a/typescript/ticket-reservation/src/ticket_db.ts
+++ b/typescript/ticket-reservation/src/ticket_db.ts
@@ -19,7 +19,7 @@ enum TicketStatus {
 
 const doReserveTicket = async (ctx: restate.RpcContext) => {
   const status =
-    (await ctx.get<TicketStatus>("status")) || TicketStatus.Available;
+    (await ctx.get<TicketStatus>("status")) ?? TicketStatus.Available;
 
   if (status === TicketStatus.Available) {
     ctx.set("status", TicketStatus.Reserved);
@@ -31,7 +31,7 @@ const doReserveTicket = async (ctx: restate.RpcContext) => {
 
 const doUnreserveTicket = async (ctx: restate.RpcContext) => {
   const status =
-    (await ctx.get<TicketStatus>("status")) || TicketStatus.Available;
+    (await ctx.get<TicketStatus>("status")) ?? TicketStatus.Available;
 
   if (status === TicketStatus.Sold) {
     return false;
@@ -43,7 +43,7 @@ const doUnreserveTicket = async (ctx: restate.RpcContext) => {
 
 const doMarkAsSold = async (ctx: restate.RpcContext) => {
   const status =
-    (await ctx.get<TicketStatus>("status")) || TicketStatus.Available;
+    (await ctx.get<TicketStatus>("status")) ?? TicketStatus.Available;
 
   if (status === TicketStatus.Reserved) {
     ctx.set("status", TicketStatus.Sold);
diff --git a/typescript/ticket-reservation/src/user_session.ts b/typescript/ticket-reservation/src/user_session.ts
index 51098cc5..58b59e1d 100644
--- a/typescript/ticket-reservation/src/user_session.ts
+++ b/typescript/ticket-reservation/src/user_session.ts
@@ -23,7 +23,7 @@ const doAddTicket = async (
 
   if (reservation_response) {
     // add ticket to user session items
-    const tickets = (await ctx.get<string[]>("items")) || [];
+    const tickets = (await ctx.get<string[]>("items")) ?? [];
     tickets.push(ticketId);
     ctx.set("items", tickets);
 
@@ -42,7 +42,7 @@ const doExpireTicket = async (
   ticketId: string
 ) => {
   ctx.send(ticketDbApi).unreserve(ticketId);
-  const tickets = (await ctx.get<string[]>("items")) || [];
+  const tickets = (await ctx.get<string[]>("items")) ?? [];
 
   const index = tickets.findIndex((id) => id === ticketId);