diff --git a/Microsoft.Azure.Cosmos/src/Handler/RequestInvokerHandler.cs b/Microsoft.Azure.Cosmos/src/Handler/RequestInvokerHandler.cs
index db08861171..29f5e9a745 100644
--- a/Microsoft.Azure.Cosmos/src/Handler/RequestInvokerHandler.cs
+++ b/Microsoft.Azure.Cosmos/src/Handler/RequestInvokerHandler.cs
@@ -18,6 +18,7 @@ namespace Microsoft.Azure.Cosmos.Handlers
     /// </summary>
     internal class RequestInvokerHandler : RequestHandler
     {
+        private static (bool, ResponseMessage) clientIsValid = (false, null);
         private readonly CosmosClient client;
         private Cosmos.ConsistencyLevel? AccountConsistencyLevel = null;
         private Cosmos.ConsistencyLevel? RequestedClientConsistencyLevel;
@@ -45,7 +46,12 @@ public override async Task<ResponseMessage> SendAsync(
             }
 
             await this.ValidateAndSetConsistencyLevelAsync(request);
-            await this.client.DocumentClient.EnsureValidClientAsync();
+            (bool isError, ResponseMessage errorResponse) = await this.EnsureValidClientAsync(request);
+            if (isError)
+            {
+                return errorResponse;
+            }
+
             await request.AssertPartitioningDetailsAsync(this.client, cancellationToken);
             this.FillMultiMasterContext(request);
             return await base.SendAsync(request, cancellationToken);
@@ -178,6 +184,19 @@ internal static HttpMethod GetHttpMethod(
             }
         }
 
+        private async Task<(bool, ResponseMessage)> EnsureValidClientAsync(RequestMessage request)
+        {
+            try
+            {
+                await this.client.DocumentClient.EnsureValidClientAsync();
+                return RequestInvokerHandler.clientIsValid;
+            }
+            catch (DocumentClientException dce)
+            {
+                return (true, dce.ToCosmosResponseMessage(request));
+            }
+        }
+
         private void FillMultiMasterContext(RequestMessage request)
         {
             if (this.client.DocumentClient.UseMultipleWriteLocations)
diff --git a/Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.EmulatorTests/CosmosPermissionTests.cs b/Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.EmulatorTests/CosmosPermissionTests.cs
index 7fa6a784aa..ce6db1de54 100644
--- a/Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.EmulatorTests/CosmosPermissionTests.cs
+++ b/Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.EmulatorTests/CosmosPermissionTests.cs
@@ -9,6 +9,7 @@ namespace Microsoft.Azure.Cosmos.SDK.EmulatorTests
     using System.Net;
     using System.Threading.Tasks;
     using Microsoft.Azure.Cosmos.Scripts;
+    using Microsoft.Azure.Cosmos.Utils;
     using Microsoft.VisualStudio.TestTools.UnitTesting;
 
     [TestClass]
@@ -221,5 +222,22 @@ public async Task ItemResourcePermissionTest()
                 Assert.AreEqual(HttpStatusCode.NoContent, response.StatusCode);
             }
         }
+
+        [TestMethod]
+        public async Task EnsureUnauthorized_ThrowsCosmosClientException()
+        {
+            string authKey = ConfigurationManager.AppSettings["MasterKey"];
+            string endpoint = ConfigurationManager.AppSettings["GatewayEndpoint"];
+
+            // Take the key and change some middle character
+            authKey = authKey.Replace("m", "M");
+
+            CosmosClient cosmosClient = new CosmosClient(
+                endpoint,
+                authKey);
+
+            CosmosException exception = await Assert.ThrowsExceptionAsync<CosmosException>(() => cosmosClient.GetContainer("test", "test").ReadItemAsync<dynamic>("test", new PartitionKey("test")));
+            Assert.AreEqual(HttpStatusCode.Unauthorized, exception.StatusCode);
+        }
     }
 }
diff --git a/changelog.md b/changelog.md
index e77179c01d..8400b94627 100644
--- a/changelog.md
+++ b/changelog.md
@@ -25,6 +25,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - [#761](https://github.com/Azure/azure-cosmos-dotnet-v3/pull/761) CosmosClient deadlocks when using a custom Task Scheduler like Orleans (Thanks to jkonecki)
 - [#769](https://github.com/Azure/azure-cosmos-dotnet-v3/pull/769) Session Consistency + Gateway mode session-token bug fix: Under few rare non-success cases session token might be in-correct
 - [#772](https://github.com/Azure/azure-cosmos-dotnet-v3/pull/772) Fixed Throughput throwing when custom serializer used or offer doesn't exists
+- [#785](https://github.com/Azure/azure-cosmos-dotnet-v3/pull/785) Incorrect key to throw CosmosExceptions with HttpStatusCode.Unauthorized status code
 
 ## [3.1.1](https://www.nuget.org/packages/Microsoft.Azure.Cosmos/3.1.1) - 2019-08-12