diff --git a/projects/RabbitMQ.Client/client/impl/WireFormatting.cs b/projects/RabbitMQ.Client/client/impl/WireFormatting.cs
index 1ade155571..bcde4bf165 100644
--- a/projects/RabbitMQ.Client/client/impl/WireFormatting.cs
+++ b/projects/RabbitMQ.Client/client/impl/WireFormatting.cs
@@ -432,8 +432,13 @@ public static int WriteShortstr(Memory<byte> memory, string val)
             if (MemoryMarshal.TryGetArray(memory, out ArraySegment<byte> segment))
             {
                 int bytesWritten = Encoding.UTF8.GetBytes(val, 0, val.Length, segment.Array, segment.Offset + 1);
-                memory.Span[0] = (byte)bytesWritten;
-                return bytesWritten + 1;
+                if (bytesWritten <= byte.MaxValue)
+                {
+                    memory.Span[0] = (byte)bytesWritten;
+                   return bytesWritten + 1;
+                }
+
+                throw new ArgumentOutOfRangeException(nameof(val), val, "Value exceeds the maximum allowed length of 255 bytes.");
             }
 
             throw new WireFormattingException("Unable to get array segment from memory.");
diff --git a/projects/Unit/TestFieldTableFormatting.cs b/projects/Unit/TestFieldTableFormatting.cs
index 7f26c0e743..1025adb7a4 100644
--- a/projects/Unit/TestFieldTableFormatting.cs
+++ b/projects/Unit/TestFieldTableFormatting.cs
@@ -38,6 +38,7 @@
 //  Copyright (c) 2007-2020 VMware, Inc.  All rights reserved.
 //---------------------------------------------------------------------------
 
+using System;
 using System.Collections;
 using System.Text;
 
@@ -127,6 +128,20 @@ public void TestTableEncoding_x()
                 });
         }
 
+        [Test]
+        public void TestTableEncoding_LongKey()
+        {
+            const int TooLarge = 256;
+            Hashtable t = new Hashtable
+            {
+                [new string('A', TooLarge)] = null
+            };
+            int bytesNeeded = WireFormatting.GetTableByteCount(t);
+            byte[] bytes = new byte[bytesNeeded];
+
+            Assert.Throws<ArgumentOutOfRangeException>(() => WireFormatting.WriteTable(bytes, t));
+        }
+
         [Test]
         public void TestQpidJmsTypes()
         {