diff --git a/src/Umbraco.Core/Runtime/SqlMainDomLock.cs b/src/Umbraco.Core/Runtime/SqlMainDomLock.cs
index 4433a8e307..27b016b2af 100644
--- a/src/Umbraco.Core/Runtime/SqlMainDomLock.cs
+++ b/src/Umbraco.Core/Runtime/SqlMainDomLock.cs
@@ -3,8 +3,10 @@ using System.Data;
 using System.Data.SqlClient;
 using System.Diagnostics;
 using System.Linq;
+using System.Security.Cryptography;
 using System.Threading;
 using System.Threading.Tasks;
+using System.Web;
 using Umbraco.Core.Logging;
 using Umbraco.Core.Persistence;
 using Umbraco.Core.Persistence.Dtos;
@@ -16,7 +18,7 @@ namespace Umbraco.Core.Runtime
     internal class SqlMainDomLock : IMainDomLock
     {
         private string _lockId;
-        private const string MainDomKey = "Umbraco.Core.Runtime.SqlMainDom";
+        private const string MainDomKeyPrefix = "Umbraco.Core.Runtime.SqlMainDom";
         private const string UpdatedSuffix = "_updated";
         private readonly ILogger _logger;
         private IUmbracoDatabase _db;
@@ -119,6 +121,16 @@ namespace Umbraco.Core.Runtime
 
         }
 
+        /// <summary>
+        /// Returns the keyvalue table key for the current server/app
+        /// </summary>
+        /// <remarks>
+        /// The key is the the normal MainDomId which takes into account the AppDomainAppId and the physical file path of the app and this is
+        /// combined with the current machine name. The machine name is required because the default semaphore lock is machine wide so it implicitly
+        /// takes into account machine name whereas this needs to be explicitly per machine.
+        /// </remarks>
+        private string MainDomKey { get; } = MainDomKeyPrefix + "-" + (NetworkHelper.MachineName + MainDom.GetMainDomId()).GenerateHash<SHA1>();
+
         private void ListeningLoop()
         {
             while (true)