diff --git a/src/Kestrel.Core/Internal/Http/Http1MessageBody.cs b/src/Kestrel.Core/Internal/Http/Http1MessageBody.cs
index e75f7e7255..3d808838b9 100644
--- a/src/Kestrel.Core/Internal/Http/Http1MessageBody.cs
+++ b/src/Kestrel.Core/Internal/Http/Http1MessageBody.cs
@@ -230,6 +230,16 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                 keepAlive = (connectionOptions & ConnectionOptions.KeepAlive) == ConnectionOptions.KeepAlive;
             }
 
+            if (upgrade)
+            {
+                if (headers.HeaderTransferEncoding.Count > 0 || (headers.ContentLength.HasValue && headers.ContentLength.Value != 0))
+                {
+                    context.ThrowRequestRejected(RequestRejectionReason.UpgradeRequestCannotHavePayload);
+                }
+
+                return new ForUpgrade(context);
+            }
+
             var transferEncoding = headers.HeaderTransferEncoding;
             if (transferEncoding.Count > 0)
             {
@@ -246,11 +256,6 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                     context.ThrowRequestRejected(RequestRejectionReason.FinalTransferCodingNotChunked, transferEncoding.ToString());
                 }
 
-                if (upgrade)
-                {
-                    context.ThrowRequestRejected(RequestRejectionReason.UpgradeRequestCannotHavePayload);
-                }
-
                 return new ForChunkedEncoding(keepAlive, context);
             }
 
@@ -262,10 +267,6 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                 {
                     return keepAlive ? MessageBody.ZeroContentLengthKeepAlive : MessageBody.ZeroContentLengthClose;
                 }
-                else if (upgrade)
-                {
-                    context.ThrowRequestRejected(RequestRejectionReason.UpgradeRequestCannotHavePayload);
-                }
 
                 return new ForContentLength(keepAlive, contentLength, context);
             }
@@ -282,11 +283,6 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                 }
             }
 
-            if (upgrade)
-            {
-                return new ForUpgrade(context);
-            }
-
             return keepAlive ? MessageBody.ZeroContentLengthKeepAlive : MessageBody.ZeroContentLengthClose;
         }
 
diff --git a/test/Kestrel.Core.Tests/MessageBodyTests.cs b/test/Kestrel.Core.Tests/MessageBodyTests.cs
index 76ecd86f7f..9fa5b6ef1a 100644
--- a/test/Kestrel.Core.Tests/MessageBodyTests.cs
+++ b/test/Kestrel.Core.Tests/MessageBodyTests.cs
@@ -503,6 +503,32 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             }
         }
 
+        [Fact]
+        public async Task UpgradeConnectionAcceptsContentLengthZero()
+        {
+            // https://tools.ietf.org/html/rfc7230#section-3.3.2
+            // "A user agent SHOULD NOT send a Content-Length header field when the request message does not contain
+            // a payload body and the method semantics do not anticipate such a body."
+            //  ==> it can actually send that header
+            var headerConnection = "Upgrade, Keep-Alive";
+            using (var input = new TestInput())
+            {
+                var body = Http1MessageBody.For(HttpVersion.Http11, new HttpRequestHeaders { HeaderConnection = headerConnection, ContentLength = 0 }, input.Http1Connection);
+                var stream = new HttpRequestStream(Mock.Of<IHttpBodyControlFeature>());
+                stream.StartAcceptingReads(body);
+
+                input.Add("Hello");
+
+                var buffer = new byte[1024];
+                Assert.Equal(5, await stream.ReadAsync(buffer, 0, buffer.Length));
+                AssertASCII("Hello", new ArraySegment<byte>(buffer, 0, 5));
+
+                input.Fin();
+
+                await body.StopAsync();
+            }
+        }
+
         [Fact]
         public async Task PumpAsyncDoesNotReturnAfterCancelingInput()
         {