diff --git a/FuelSDK-CSharp/ETClient.cs b/FuelSDK-CSharp/ETClient.cs
index ff4d5d7..c831245 100644
--- a/FuelSDK-CSharp/ETClient.cs
+++ b/FuelSDK-CSharp/ETClient.cs
@@ -20,7 +20,7 @@ namespace FuelSDK
     /// </summary>
     public class ETClient
     {
-        public const string SDKVersion = "FuelSDK-C#-v1.1.0";
+        public const string SDKVersion = "FuelSDK-C#-v1.1.1";
 
         private FuelSDKConfigurationSection configSection;
         public string AuthToken { get; private set; }
@@ -31,13 +31,30 @@ public class ETClient
         public JObject Jwt { get; private set; }
         public string EnterpriseId { get; private set; }
         public string OrganizationId { get; private set; }
-        public string Stack { get; private set; }
+        private string stackKey;
+        [Obsolete(StackKeyErrorMessage)]
+        public string Stack
+        {
+            get {
+                if (stackKey != null)
+                    return stackKey;
+
+                stackKey = GetStackFromSoapEndPoint(new Uri(configSection.SoapEndPoint));
+                return stackKey;
+            }
+            private set
+            {
+                stackKey = value;
+            }
+        }
 
         private static DateTime soapEndPointExpiration;
         private static DateTime stackKeyExpiration;
         private static string fetchedSoapEndpoint;
         private const long cacheDurationInMinutes = 10;
 
+        private const string StackKeyErrorMessage = "Tenant specific endpoints doesn't support Stack Key property and this will property will be deprecated in next major release";
+
         public class RefreshState
         {
             public string RefreshKey { get; set; }
@@ -143,7 +160,6 @@ public ETClient(NameValueCollection parameters = null, RefreshState refreshState
                     {
                         EnterpriseId = results[0].Client.EnterpriseID.ToString();
                         OrganizationId = results[0].ID.ToString();
-                        Stack = StackKey.Instance.Get(long.Parse(EnterpriseId), this);
                     }
                 }
         }
@@ -193,6 +209,14 @@ private string DecodeJWT(string jwt, string key)
             return json;
         }
 
+        private string GetStackFromSoapEndPoint(Uri uri)
+        {
+            var parts = uri.Host.Split('.');
+            if (parts.Length < 2 || !parts[0].Equals("webservice", StringComparison.OrdinalIgnoreCase))
+                throw new Exception(StackKeyErrorMessage);
+            return (parts[1] == "exacttarget" ? "s1" : parts[1].ToLower());
+        }
+
         private static Binding GetSoapBinding()
         {
             return new CustomBinding(new BindingElementCollection
diff --git a/FuelSDK-Test/ETClientTest.cs b/FuelSDK-Test/ETClientTest.cs
index 9703d94..9b218c4 100644
--- a/FuelSDK-Test/ETClientTest.cs
+++ b/FuelSDK-Test/ETClientTest.cs
@@ -17,14 +17,6 @@ public void Setup()
             client2 = new ETClient();
         }
 
-        [Test()]
-        public void GetClientStack()
-        {
-            Assert.IsNotNull(client1.Stack);
-            Assert.IsNotNull(client2.Stack);
-            Assert.AreEqual(client1.Stack, client2.Stack);
-        }
-
         [Test()]
         public void TestSoapEndpointCaching()
         {
diff --git a/FuelSDK-Test/StackKeyTest.cs b/FuelSDK-Test/StackKeyTest.cs
index c39aa40..5658140 100644
--- a/FuelSDK-Test/StackKeyTest.cs
+++ b/FuelSDK-Test/StackKeyTest.cs
@@ -1,19 +1,35 @@
 using NUnit.Framework;
+using System;
+using System.Linq;
 
 namespace FuelSDK.Test
 {
     [TestFixture]
     public class StackKeyTest
     {
+        private const string StackKeyErrorMessage = "Tenant specific endpoints doesn't support Stack Key property and this will property will be deprecated in next major release";
+
+        [Test]
+        public void ExceptionOccursIfTSEFormatIsUsedForSoapEndpoint()
+        {
+            var client = new ETClient();
+
+            var exception = Assert.Throws<Exception>(
+                () => { var stack = client.Stack; }
+            );
+
+            Assert.That(exception.Message, Is.EqualTo(StackKeyErrorMessage));
+        }
+
         [Test]
-        public void MultipleETClientInstancesForTheSameClientIdAndSecretWillHaveTheSameStackKey()
+        public void StackPropertyIsMarkedAsObsolete()
         {
-            ETClient client1 = new ETClient();
-            ETClient client2 = new ETClient();
+            var type = typeof(ETClient);
+            var obsoleteAttributes = (ObsoleteAttribute[])type.GetProperty("Stack").GetCustomAttributes(typeof(ObsoleteAttribute), false);
 
-            Assert.IsNotNull(client1.Stack);
-            Assert.IsNotNull(client2.Stack);
-            Assert.AreEqual(client1.Stack, client2.Stack);
+            Assert.AreEqual(1, obsoleteAttributes.Length);
+            Assert.AreEqual(StackKeyErrorMessage, obsoleteAttributes[0].Message);
+            Assert.AreEqual(false, obsoleteAttributes[0].IsError);
         }
     }
 }
diff --git a/README.md b/README.md
index b7c0729..d7328bd 100644
--- a/README.md
+++ b/README.md
@@ -6,6 +6,9 @@ Salesforce Marketing Cloud Fuel SDK for C#
 ## Overview ##
 The Fuel SDK for C# provides easy access to Salesforce Marketing Cloud's Fuel API Family services, including a collection of REST APIs and a SOAP API. These APIs provide access to Salesforce Marketing Cloud functionality via common collection types. 
 
+## Latest Version 1.1.1 ##
+* Bug fixes
+
 ## New Features in Version 1.1.0 ##
 * **Added support for your tenant's endpoints - [More Details](https://developer.salesforce.com/docs/atlas.en-us.mc-apis.meta/mc-apis/your-subdomain-tenant-specific-endpoints.htm) :** The user of the SDK can now configure them through a **App.config** file OR using the “**parameters**” **ETClient** constructor parameter as in the previous version of the SDK. The user of the SDK has to make a copy of the **App.config.transform** file which is found in the **FuelSDK-CSharp** folder, place it in the same folder and rename it to **App.config**. The structure of this file will be the following: 
 
diff --git a/nuspecs/FuelSDK-CSharp.nuspec b/nuspecs/FuelSDK-CSharp.nuspec
index d56de88..d781539 100644
--- a/nuspecs/FuelSDK-CSharp.nuspec
+++ b/nuspecs/FuelSDK-CSharp.nuspec
@@ -2,7 +2,7 @@
 <package>
   <metadata>
     <id>SFMC.FuelSDK</id>
-    <version>1.1.0</version>
+    <version>1.1.1</version>
     <title>FuelSDK-CSharp</title>
     <authors>Salesforce</authors>
     <owners>Salesforce</owners>