diff --git a/types/defines/rpc.d.ts b/types/defines/rpc.d.ts
index 724870f48f5..87cb8389a4f 100644
--- a/types/defines/rpc.d.ts
+++ b/types/defines/rpc.d.ts
@@ -235,6 +235,7 @@ declare module "cloudflare:workers" {
   export type WorkflowEvent<T> = {
     payload: Readonly<T>;
     timestamp: Date;
+    instanceId: string;
   };
 
   export abstract class WorkflowStep {
diff --git a/types/generated-snapshot/2021-11-03/index.d.ts b/types/generated-snapshot/2021-11-03/index.d.ts
index 73446c0b010..40dc1b4b7a3 100755
--- a/types/generated-snapshot/2021-11-03/index.d.ts
+++ b/types/generated-snapshot/2021-11-03/index.d.ts
@@ -5357,6 +5357,7 @@ declare module "cloudflare:workers" {
   export type WorkflowEvent<T> = {
     payload: Readonly<T>;
     timestamp: Date;
+    instanceId: string;
   };
   export abstract class WorkflowStep {
     do<T extends Rpc.Serializable<T>>(
diff --git a/types/generated-snapshot/2022-01-31/index.d.ts b/types/generated-snapshot/2022-01-31/index.d.ts
index 1d235325383..99db6c2410c 100755
--- a/types/generated-snapshot/2022-01-31/index.d.ts
+++ b/types/generated-snapshot/2022-01-31/index.d.ts
@@ -5383,6 +5383,7 @@ declare module "cloudflare:workers" {
   export type WorkflowEvent<T> = {
     payload: Readonly<T>;
     timestamp: Date;
+    instanceId: string;
   };
   export abstract class WorkflowStep {
     do<T extends Rpc.Serializable<T>>(
diff --git a/types/generated-snapshot/2022-03-21/index.d.ts b/types/generated-snapshot/2022-03-21/index.d.ts
index 716260882d2..49bdc34de58 100755
--- a/types/generated-snapshot/2022-03-21/index.d.ts
+++ b/types/generated-snapshot/2022-03-21/index.d.ts
@@ -5408,6 +5408,7 @@ declare module "cloudflare:workers" {
   export type WorkflowEvent<T> = {
     payload: Readonly<T>;
     timestamp: Date;
+    instanceId: string;
   };
   export abstract class WorkflowStep {
     do<T extends Rpc.Serializable<T>>(
diff --git a/types/generated-snapshot/2022-08-04/index.d.ts b/types/generated-snapshot/2022-08-04/index.d.ts
index 6c436cbf7c7..bf1d9759e6a 100755
--- a/types/generated-snapshot/2022-08-04/index.d.ts
+++ b/types/generated-snapshot/2022-08-04/index.d.ts
@@ -5409,6 +5409,7 @@ declare module "cloudflare:workers" {
   export type WorkflowEvent<T> = {
     payload: Readonly<T>;
     timestamp: Date;
+    instanceId: string;
   };
   export abstract class WorkflowStep {
     do<T extends Rpc.Serializable<T>>(
diff --git a/types/generated-snapshot/2022-10-31/index.d.ts b/types/generated-snapshot/2022-10-31/index.d.ts
index 76c16607577..f92c277233d 100755
--- a/types/generated-snapshot/2022-10-31/index.d.ts
+++ b/types/generated-snapshot/2022-10-31/index.d.ts
@@ -5412,6 +5412,7 @@ declare module "cloudflare:workers" {
   export type WorkflowEvent<T> = {
     payload: Readonly<T>;
     timestamp: Date;
+    instanceId: string;
   };
   export abstract class WorkflowStep {
     do<T extends Rpc.Serializable<T>>(
diff --git a/types/generated-snapshot/2022-11-30/index.d.ts b/types/generated-snapshot/2022-11-30/index.d.ts
index 2ef04b83206..fc2453b6dfc 100755
--- a/types/generated-snapshot/2022-11-30/index.d.ts
+++ b/types/generated-snapshot/2022-11-30/index.d.ts
@@ -5417,6 +5417,7 @@ declare module "cloudflare:workers" {
   export type WorkflowEvent<T> = {
     payload: Readonly<T>;
     timestamp: Date;
+    instanceId: string;
   };
   export abstract class WorkflowStep {
     do<T extends Rpc.Serializable<T>>(
diff --git a/types/generated-snapshot/2023-03-01/index.d.ts b/types/generated-snapshot/2023-03-01/index.d.ts
index 672cc7c8e2d..d6842e18978 100755
--- a/types/generated-snapshot/2023-03-01/index.d.ts
+++ b/types/generated-snapshot/2023-03-01/index.d.ts
@@ -5419,6 +5419,7 @@ declare module "cloudflare:workers" {
   export type WorkflowEvent<T> = {
     payload: Readonly<T>;
     timestamp: Date;
+    instanceId: string;
   };
   export abstract class WorkflowStep {
     do<T extends Rpc.Serializable<T>>(
diff --git a/types/generated-snapshot/2023-07-01/index.d.ts b/types/generated-snapshot/2023-07-01/index.d.ts
index aa84a7f72fe..e020d940799 100755
--- a/types/generated-snapshot/2023-07-01/index.d.ts
+++ b/types/generated-snapshot/2023-07-01/index.d.ts
@@ -5419,6 +5419,7 @@ declare module "cloudflare:workers" {
   export type WorkflowEvent<T> = {
     payload: Readonly<T>;
     timestamp: Date;
+    instanceId: string;
   };
   export abstract class WorkflowStep {
     do<T extends Rpc.Serializable<T>>(
diff --git a/types/generated-snapshot/experimental/index.d.ts b/types/generated-snapshot/experimental/index.d.ts
index a357db887d0..7b835692eb0 100755
--- a/types/generated-snapshot/experimental/index.d.ts
+++ b/types/generated-snapshot/experimental/index.d.ts
@@ -5485,6 +5485,7 @@ declare module "cloudflare:workers" {
   export type WorkflowEvent<T> = {
     payload: Readonly<T>;
     timestamp: Date;
+    instanceId: string;
   };
   export abstract class WorkflowStep {
     do<T extends Rpc.Serializable<T>>(
diff --git a/types/generated-snapshot/oldest/index.d.ts b/types/generated-snapshot/oldest/index.d.ts
index dee1a367cf6..ed092c279a8 100755
--- a/types/generated-snapshot/oldest/index.d.ts
+++ b/types/generated-snapshot/oldest/index.d.ts
@@ -5357,6 +5357,7 @@ declare module "cloudflare:workers" {
   export type WorkflowEvent<T> = {
     payload: Readonly<T>;
     timestamp: Date;
+    instanceId: string;
   };
   export abstract class WorkflowStep {
     do<T extends Rpc.Serializable<T>>(