diff --git a/Source/DiscoveryV1/Discovery.swift b/Source/DiscoveryV1/Discovery.swift
index ac9830cac..e9901899f 100644
--- a/Source/DiscoveryV1/Discovery.swift
+++ b/Source/DiscoveryV1/Discovery.swift
@@ -118,7 +118,8 @@ public class Discovery {
 
      - parameter name: Name that identifies the environment.
      - parameter description: Description of the environment.
-     - parameter size: Size of the environment.
+     - parameter size: Size of the environment. In the Lite plan the default and only accepted value is `LT`, in all
+       other plans the default is `S`.
      - parameter headers: A dictionary of request headers to be sent with this request.
      - parameter failure: A function executed if an error occurs.
      - parameter success: A function executed with the successful result.
@@ -284,6 +285,8 @@ public class Discovery {
      - parameter environmentID: The ID of the environment.
      - parameter name: Name that identifies the environment.
      - parameter description: Description of the environment.
+     - parameter size: Size that the environment should be increased to. Environment size cannot be modified when
+       using a Lite plan. Environment size can only increased and not decreased.
      - parameter headers: A dictionary of request headers to be sent with this request.
      - parameter failure: A function executed if an error occurs.
      - parameter success: A function executed with the successful result.
@@ -292,12 +295,13 @@ public class Discovery {
         environmentID: String,
         name: String? = nil,
         description: String? = nil,
+        size: String? = nil,
         headers: [String: String]? = nil,
         failure: ((Error) -> Void)? = nil,
         success: @escaping (Environment) -> Void)
     {
         // construct body
-        let updateEnvironmentRequest = UpdateEnvironmentRequest(name: name, description: description)
+        let updateEnvironmentRequest = UpdateEnvironmentRequest(name: name, description: description, size: size)
         guard let body = try? JSONEncoder().encode(updateEnvironmentRequest) else {
             failure?(RestError.serializationError)
             return
diff --git a/Source/DiscoveryV1/Models/UpdateEnvironmentRequest.swift b/Source/DiscoveryV1/Models/UpdateEnvironmentRequest.swift
index 6ed15a0a5..d66271c33 100644
--- a/Source/DiscoveryV1/Models/UpdateEnvironmentRequest.swift
+++ b/Source/DiscoveryV1/Models/UpdateEnvironmentRequest.swift
@@ -19,6 +19,21 @@ import Foundation
 /** UpdateEnvironmentRequest. */
 internal struct UpdateEnvironmentRequest: Encodable {
 
+    /**
+     Size that the environment should be increased to. Environment size cannot be modified when using a Lite plan.
+     Environment size can only increased and not decreased.
+     */
+    public enum Size: String {
+        case s = "S"
+        case ms = "MS"
+        case m = "M"
+        case ml = "ML"
+        case l = "L"
+        case xl = "XL"
+        case xxl = "XXL"
+        case xxxl = "XXXL"
+    }
+
     /**
      Name that identifies the environment.
      */
@@ -29,10 +44,17 @@ internal struct UpdateEnvironmentRequest: Encodable {
      */
     public var description: String?
 
+    /**
+     Size that the environment should be increased to. Environment size cannot be modified when using a Lite plan.
+     Environment size can only increased and not decreased.
+     */
+    public var size: String?
+
     // Map each property name to the key that shall be used for encoding/decoding.
     private enum CodingKeys: String, CodingKey {
         case name = "name"
         case description = "description"
+        case size = "size"
     }
 
     /**
@@ -40,16 +62,20 @@ internal struct UpdateEnvironmentRequest: Encodable {
 
      - parameter name: Name that identifies the environment.
      - parameter description: Description of the environment.
+     - parameter size: Size that the environment should be increased to. Environment size cannot be modified when
+       using a Lite plan. Environment size can only increased and not decreased.
 
      - returns: An initialized `UpdateEnvironmentRequest`.
     */
     public init(
         name: String? = nil,
-        description: String? = nil
+        description: String? = nil,
+        size: String? = nil
     )
     {
         self.name = name
         self.description = description
+        self.size = size
     }
 
 }