diff --git a/src/GitVersionCore.Tests/ExecuteCoreTests.cs b/src/GitVersionCore.Tests/ExecuteCoreTests.cs
index 04ad8fc674..3112cdd5f5 100644
--- a/src/GitVersionCore.Tests/ExecuteCoreTests.cs
+++ b/src/GitVersionCore.Tests/ExecuteCoreTests.cs
@@ -7,6 +7,7 @@
 using System;
 using System.IO;
 using System.Text;
+using LibGit2Sharp;
 
 [TestFixture]
 [Parallelizable(ParallelScope.None)]
@@ -40,6 +41,35 @@ public void CacheKeySameAfterReNormalizing()
         });
     }
 
+    [Test]
+    [Category("NoMono")]
+    [Description("LibGit2Sharp fails here when running under Mono")]
+    public void CacheKeyForWorktree()
+    {
+        var versionAndBranchFinder = new ExecuteCore(fileSystem);
+
+        RepositoryScope(versionAndBranchFinder, (fixture, vv) =>
+        {
+            var worktreePath = Path.Combine(Directory.GetParent(fixture.RepositoryPath).FullName, Guid.NewGuid().ToString());
+            try
+            {
+                // create a branch and a new worktree for it
+                var repo = new Repository(fixture.RepositoryPath);
+                repo.Worktrees.Add("worktree", worktreePath, false);
+
+                var targetUrl = "https://github.com/GitTools/GitVersion.git";
+                var gitPreparer = new GitPreparer(targetUrl, null, new Authentication(), false, worktreePath);
+                var configFileLocator = new DefaultConfigFileLocator();
+                var cacheKey = GitVersionCacheKeyFactory.Create(fileSystem, gitPreparer, null, configFileLocator);
+                cacheKey.Value.ShouldNotBeEmpty();
+            }
+            finally
+            {
+                DirectoryHelper.DeleteDirectory(worktreePath);
+            }
+        });
+    }
+
     [Test]
     public void CacheFileExistsOnDisk()
     {
@@ -266,6 +296,47 @@ public void WorkingDirectoryWithoutGit()
         });
     }
 
+    [Test]
+    [Category("NoMono")]
+    [Description("LibGit2Sharp fails when running under Mono")]
+    public void GetProjectRootDirectory_WorkingDirectoryWithWorktree()
+    {
+        var versionAndBranchFinder = new ExecuteCore(fileSystem);
+
+        RepositoryScope(versionAndBranchFinder, (fixture, vv) =>
+        {
+            var worktreePath = Path.Combine(Directory.GetParent(fixture.RepositoryPath).FullName, Guid.NewGuid().ToString());
+            try
+            {
+                // create a branch and a new worktree for it
+                var repo = new Repository(fixture.RepositoryPath);
+                repo.Worktrees.Add("worktree", worktreePath, false);
+
+                var targetUrl = "https://github.com/GitTools/GitVersion.git";
+                var gitPreparer = new GitPreparer(targetUrl, null, new Authentication(), false, worktreePath);
+                gitPreparer.GetProjectRootDirectory().TrimEnd('/', '\\').ShouldBe(worktreePath);
+            }
+            finally
+            {
+                DirectoryHelper.DeleteDirectory(worktreePath);
+            }
+        });
+    }
+
+    [Test]
+    public void GetProjectRootDirectory_NoWorktree()
+    {
+        var versionAndBranchFinder = new ExecuteCore(fileSystem);
+
+        RepositoryScope(versionAndBranchFinder, (fixture, vv) =>
+        {
+            var targetUrl = "https://github.com/GitTools/GitVersion.git";
+            var gitPreparer = new GitPreparer(targetUrl, null, new Authentication(), false, fixture.RepositoryPath);
+            var expectedPath = fixture.RepositoryPath.TrimEnd('/', '\\');
+            gitPreparer.GetProjectRootDirectory().TrimEnd('/', '\\').ShouldBe(expectedPath);
+        });
+    }
+
     [Test]
     public void DynamicRepositoriesShouldNotErrorWithFailedToFindGitDirectory()
     {
@@ -277,6 +348,48 @@ public void DynamicRepositoriesShouldNotErrorWithFailedToFindGitDirectory()
         });
     }
 
+    [Test]
+    public void GetDotGitDirectory_NoWorktree()
+    {
+        var versionAndBranchFinder = new ExecuteCore(fileSystem);
+
+        RepositoryScope(versionAndBranchFinder, (fixture, vv) =>
+        {
+            var targetUrl = "https://github.com/GitTools/GitVersion.git";
+            var gitPreparer = new GitPreparer(targetUrl, null, new Authentication(), false, fixture.RepositoryPath);
+            var expectedPath = Path.Combine(fixture.RepositoryPath, ".git");
+            gitPreparer.GetDotGitDirectory().ShouldBe(expectedPath);
+        });
+    }
+
+    [Test]
+    [Category("NoMono")]
+    [Description("LibGit2Sharp fails when running under Mono")]
+    public void GetDotGitDirectory_Worktree()
+    {
+        var versionAndBranchFinder = new ExecuteCore(fileSystem);
+
+        RepositoryScope(versionAndBranchFinder, (fixture, vv) =>
+        {
+            var worktreePath = Path.Combine(Directory.GetParent(fixture.RepositoryPath).FullName, Guid.NewGuid().ToString());
+            try
+            {
+                // create a branch and a new worktree for it
+                var repo = new Repository(fixture.RepositoryPath);
+                repo.Worktrees.Add("worktree", worktreePath, false);
+
+                var targetUrl = "https://github.com/GitTools/GitVersion.git";
+                var gitPreparer = new GitPreparer(targetUrl, null, new Authentication(), false, worktreePath);
+                var expectedPath = Path.Combine(fixture.RepositoryPath, ".git");
+                gitPreparer.GetDotGitDirectory().ShouldBe(expectedPath);
+            }
+            finally
+            {
+                DirectoryHelper.DeleteDirectory(worktreePath);
+            }
+        });
+    }
+
     LogMessages RepositoryScope(ExecuteCore executeCore = null, Action<EmptyRepositoryFixture, VersionVariables> fixtureAction = null)
     {
         // Make sure GitVersion doesn't trigger build server mode when we are running the tests
diff --git a/src/GitVersionCore/GitPreparer.cs b/src/GitVersionCore/GitPreparer.cs
index b9f9d52c97..a734dfd8b5 100644
--- a/src/GitVersionCore/GitPreparer.cs
+++ b/src/GitVersionCore/GitPreparer.cs
@@ -135,17 +135,14 @@ static bool GitRepoHasMatchingRemote(string possiblePath, string targetUrl)
 
         public string GetDotGitDirectory()
         {
-            if (IsDynamicGitRepository)
-                return DynamicGitRepositoryPath;
-
-            var dotGitDirectory = Repository.Discover(targetPath);
+            var dotGitDirectory = IsDynamicGitRepository ? DynamicGitRepositoryPath : Repository.Discover(targetPath);
 
+            dotGitDirectory = dotGitDirectory?.TrimEnd('/', '\\');
             if (string.IsNullOrEmpty(dotGitDirectory))
                 throw new DirectoryNotFoundException("Can't find the .git directory in " + targetPath);
 
-            dotGitDirectory = dotGitDirectory.TrimEnd('/', '\\');
-            if (string.IsNullOrEmpty(dotGitDirectory))
-                throw new DirectoryNotFoundException("Can't find the .git directory in " + targetPath);
+            if (dotGitDirectory.Contains(Path.Combine(".git", "worktrees")))
+                return Directory.GetParent(Directory.GetParent(dotGitDirectory).FullName).FullName;
 
             return dotGitDirectory;
         }
@@ -159,10 +156,17 @@ public string GetProjectRootDirectory()
                 return targetPath;
             }
 
-            var dotGetGitDirectory = GetDotGitDirectory();
-            var result = Directory.GetParent(dotGetGitDirectory).FullName;
-            Logger.WriteInfo($"Returning Project Root from DotGitDirectory: {dotGetGitDirectory} - {result}");
-            return result;
+            var dotGitDirectory = Repository.Discover(targetPath);
+
+            if (string.IsNullOrEmpty(dotGitDirectory))
+                throw new DirectoryNotFoundException($"Can't find the .git directory in {targetPath}");
+
+            using (var repo = new Repository(dotGitDirectory))
+            {
+                var result = repo.Info.WorkingDirectory;
+                Logger.WriteInfo($"Returning Project Root from DotGitDirectory: {dotGitDirectory} - {result}");
+                return result;
+            }
         }
 
         static string CreateDynamicRepository(string targetPath, AuthenticationInfo authentication, string repositoryUrl, string targetBranch, bool noFetch)
diff --git a/src/GitVersionCore/GitVersionCacheKeyFactory.cs b/src/GitVersionCore/GitVersionCacheKeyFactory.cs
index dfd917ac2d..06670d9d65 100644
--- a/src/GitVersionCore/GitVersionCacheKeyFactory.cs
+++ b/src/GitVersionCore/GitVersionCacheKeyFactory.cs
@@ -42,7 +42,7 @@ static List<string> CalculateDirectoryContents(string root)
 
             if (!Directory.Exists(root))
             {
-                throw new ArgumentException();
+                throw new DirectoryNotFoundException($"Root directory does not exist: {root}");
             }
 
             dirs.Push(root);