diff --git a/Sources/AWSLambdaEvents/ALB.swift b/Sources/AWSLambdaEvents/ALB.swift
index 121531a6..536756da 100644
--- a/Sources/AWSLambdaEvents/ALB.swift
+++ b/Sources/AWSLambdaEvents/ALB.swift
@@ -51,12 +51,12 @@ public enum ALB {
     }
 
     public struct TargetGroupResponse: Codable {
-        public let statusCode: HTTPResponseStatus
-        public let statusDescription: String?
-        public let headers: HTTPHeaders?
-        public let multiValueHeaders: HTTPMultiValueHeaders?
-        public let body: String
-        public let isBase64Encoded: Bool
+        public var statusCode: HTTPResponseStatus
+        public var statusDescription: String?
+        public var headers: HTTPHeaders?
+        public var multiValueHeaders: HTTPMultiValueHeaders?
+        public var body: String
+        public var isBase64Encoded: Bool
 
         public init(
             statusCode: HTTPResponseStatus,
diff --git a/Sources/AWSLambdaEvents/APIGateway+V2.swift b/Sources/AWSLambdaEvents/APIGateway+V2.swift
index 12c4c2ce..7b9ab0eb 100644
--- a/Sources/AWSLambdaEvents/APIGateway+V2.swift
+++ b/Sources/AWSLambdaEvents/APIGateway+V2.swift
@@ -93,24 +93,21 @@ extension APIGateway.V2 {
 
 extension APIGateway.V2 {
     public struct Response: Codable {
-        public let statusCode: HTTPResponseStatus
-        public let headers: HTTPHeaders?
-        public let multiValueHeaders: HTTPMultiValueHeaders?
-        public let body: String?
-        public let isBase64Encoded: Bool?
-        public let cookies: [String]?
+        public var statusCode: HTTPResponseStatus
+        public var headers: HTTPHeaders?
+        public var body: String?
+        public var isBase64Encoded: Bool?
+        public var cookies: [String]?
 
         public init(
             statusCode: HTTPResponseStatus,
             headers: HTTPHeaders? = nil,
-            multiValueHeaders: HTTPMultiValueHeaders? = nil,
             body: String? = nil,
             isBase64Encoded: Bool? = nil,
             cookies: [String]? = nil
         ) {
             self.statusCode = statusCode
             self.headers = headers
-            self.multiValueHeaders = multiValueHeaders
             self.body = body
             self.isBase64Encoded = isBase64Encoded
             self.cookies = cookies
diff --git a/Sources/AWSLambdaEvents/APIGateway.swift b/Sources/AWSLambdaEvents/APIGateway.swift
index 5ae961e2..a944cef2 100644
--- a/Sources/AWSLambdaEvents/APIGateway.swift
+++ b/Sources/AWSLambdaEvents/APIGateway.swift
@@ -70,11 +70,11 @@ public enum APIGateway {
 
 extension APIGateway {
     public struct Response: Codable {
-        public let statusCode: HTTPResponseStatus
-        public let headers: HTTPHeaders?
-        public let multiValueHeaders: HTTPMultiValueHeaders?
-        public let body: String?
-        public let isBase64Encoded: Bool?
+        public var statusCode: HTTPResponseStatus
+        public var headers: HTTPHeaders?
+        public var multiValueHeaders: HTTPMultiValueHeaders?
+        public var body: String?
+        public var isBase64Encoded: Bool?
 
         public init(
             statusCode: HTTPResponseStatus,