diff --git a/sdk/core/Azure.Core/CHANGELOG.md b/sdk/core/Azure.Core/CHANGELOG.md
index d061341fadb85..42ab8395ac180 100644
--- a/sdk/core/Azure.Core/CHANGELOG.md
+++ b/sdk/core/Azure.Core/CHANGELOG.md
@@ -7,6 +7,7 @@
 
 ### Fixed
 - The race condition in `AzureEventSourceListener` class that sometimes resulted in a `NullReferenceException` in the `EventSource`.
+- The overflow exception when content length is larger than `int.MaxValue`.
 
 ## 1.5.1 (2020-10-01)
 
diff --git a/sdk/core/Azure.Core/src/Pipeline/HttpWebRequestTransport.cs b/sdk/core/Azure.Core/src/Pipeline/HttpWebRequestTransport.cs
index 1187a2c711015..92a23144299a4 100644
--- a/sdk/core/Azure.Core/src/Pipeline/HttpWebRequestTransport.cs
+++ b/sdk/core/Azure.Core/src/Pipeline/HttpWebRequestTransport.cs
@@ -106,11 +106,12 @@ private HttpWebRequest CreateRequest(Request messageRequest)
             var request = WebRequest.CreateHttp(messageRequest.Uri.ToUri());
             request.Method = messageRequest.Method.Method;
             request.Proxy = _proxy;
+
             foreach (var messageRequestHeader in messageRequest.Headers)
             {
                 if (string.Equals(messageRequestHeader.Name, HttpHeader.Names.ContentLength, StringComparison.OrdinalIgnoreCase))
                 {
-                    request.ContentLength = int.Parse(messageRequestHeader.Value, CultureInfo.InvariantCulture);
+                    request.ContentLength = long.Parse(messageRequestHeader.Value, CultureInfo.InvariantCulture);
                     continue;
                 }
 
@@ -180,6 +181,12 @@ private HttpWebRequest CreateRequest(Request messageRequest)
                 request.Headers.Add(messageRequestHeader.Name, messageRequestHeader.Value);
             }
 
+            if (request.ContentLength != -1)
+            {
+                // disable buffering when the content length is known
+                // as the content stream is re-playable and we don't want to allocate extra buffers
+                request.AllowWriteStreamBuffering = false;
+            }
             return request;
         }
 
diff --git a/sdk/core/Azure.Core/tests/TestServer.cs b/sdk/core/Azure.Core/tests/TestServer.cs
index 2853e6b1ead0a..0d9229597e7a9 100644
--- a/sdk/core/Azure.Core/tests/TestServer.cs
+++ b/sdk/core/Azure.Core/tests/TestServer.cs
@@ -29,7 +29,11 @@ public TestServer(RequestDelegate app)
         {
             _app = app;
             _host = new WebHostBuilder()
-                .UseKestrel(options => options.Listen(new IPEndPoint(IPAddress.Loopback, 0)))
+                .UseKestrel(options =>
+                {
+                    options.Limits.MaxRequestBodySize = null;
+                    options.Listen(new IPEndPoint(IPAddress.Loopback, 0));
+                })
                 .ConfigureServices(services =>
                 {
                     services.AddSingleton<IStartup>(this);
diff --git a/sdk/core/Azure.Core/tests/TransportFunctionalTests.cs b/sdk/core/Azure.Core/tests/TransportFunctionalTests.cs
index 8e3cdc2e01e34..dc39216c0346f 100644
--- a/sdk/core/Azure.Core/tests/TransportFunctionalTests.cs
+++ b/sdk/core/Azure.Core/tests/TransportFunctionalTests.cs
@@ -94,6 +94,35 @@ public async Task SettingHeaderOverridesDefaultContentLength()
             Assert.AreEqual(50, contentLength);
         }
 
+        [Test]
+        public async Task CanSetContentLenghtOverMaxInt()
+        {
+            long contentLength = 0;
+            using TestServer testServer = new TestServer(
+                context =>
+                {
+                    contentLength = context.Request.ContentLength.Value;
+                });
+
+            var requestContentLength = long.MaxValue;
+            var transport = GetTransport();
+            Request request = transport.CreateRequest();
+            request.Method = RequestMethod.Post;
+            request.Uri.Reset(testServer.Address);
+            request.Content = RequestContent.Create(new byte[10]);
+            request.Headers.Add("Content-Length", requestContentLength.ToString());
+
+            try
+            {
+                await ExecuteRequest(request, transport);
+            }
+            catch (Exception)
+            {
+                // Sending the request would fail because of length mismatch
+            }
+
+            Assert.AreEqual(requestContentLength, requestContentLength);
+        }
 
         [Test]
         public async Task HostHeaderSetFromUri()