diff --git a/GitVersionCore/GitPreparer.cs b/GitVersionCore/GitPreparer.cs
index 96ffb2309d..6a2ae11a25 100644
--- a/GitVersionCore/GitPreparer.cs
+++ b/GitVersionCore/GitPreparer.cs
@@ -43,6 +43,7 @@ public void Initialise(bool normaliseGitDirectory)
             }
 
             var targetPath = CalculateTemporaryRepositoryPath(targetUrl, dynamicRepositoryLocation);
+
             DynamicGitRepositoryPath = CreateDynamicRepository(targetPath, authentication, targetUrl, targetBranch, noFetch);
             if (normaliseGitDirectory)
             {
@@ -119,6 +120,10 @@ static string CreateDynamicRepository(string targetPath, Authentication authenti
                 Logger.WriteInfo(string.Format("Updating branch '{0}'", targetBranch));
                 using (var repo = new Repository(targetPath))
                 {
+                    if (string.IsNullOrWhiteSpace(targetBranch))
+                    {
+                        throw new Exception("Dynamic Git repositories must have a target branch (/b)");
+                    }
                     var targetGitBranch = repo.Branches[targetBranch];
                     var trackedBranch = targetGitBranch.TrackedBranch;
                     if (trackedBranch == null)
diff --git a/GitVersionCore/GitVersionCore.csproj b/GitVersionCore/GitVersionCore.csproj
index b33d56ef1e..a5db778b72 100644
--- a/GitVersionCore/GitVersionCore.csproj
+++ b/GitVersionCore/GitVersionCore.csproj
@@ -138,7 +138,6 @@
     <Compile Include="LambdaEqualityHelper.cs" />
     <Compile Include="LibGitExtensions.cs" />
     <Compile Include="Logger.cs" />
-    <Compile Include="MissingBranchException.cs" />
     <Compile Include="OutputFormatters\BuildOutputFormatter.cs" />
     <Compile Include="OutputFormatters\JsonOutputFormatter.cs" />
     <Compile Include="OutputType.cs" />
diff --git a/GitVersionCore/MissingBranchException.cs b/GitVersionCore/MissingBranchException.cs
deleted file mode 100644
index e280744a5c..0000000000
--- a/GitVersionCore/MissingBranchException.cs
+++ /dev/null
@@ -1,12 +0,0 @@
-namespace GitVersion
-{
-    using System;
-    using LibGit2Sharp;
-
-    public class MissingBranchException : Exception
-    {
-        public MissingBranchException(string message, LibGit2SharpException exception):base(message,exception)
-        {
-        }
-    }
-}
\ No newline at end of file
diff --git a/GitVersionExe.Tests/GitPreparerTests.cs b/GitVersionExe.Tests/GitPreparerTests.cs
index 90a4eb9217..2dd6391c42 100644
--- a/GitVersionExe.Tests/GitPreparerTests.cs
+++ b/GitVersionExe.Tests/GitPreparerTests.cs
@@ -242,5 +242,38 @@ public void UsingDynamicRepositoryWithFeatureBranchWorks()
         }
     }
 
+    [Test]
+    public void UsingDynamicRepositoryWithoutTargetBranchFails()
+    {
+        var repoName = Guid.NewGuid().ToString();
+        var tempPath = Path.GetTempPath();
+        var tempDir = Path.Combine(tempPath, repoName);
+        Directory.CreateDirectory(tempDir);
+
+        try
+        {
+            using (var mainRepositoryFixture = new EmptyRepositoryFixture(new Config()))
+            {
+                var commitId = mainRepositoryFixture.Repository.MakeACommit().Id.Sha;
+
+                var arguments = new Arguments
+                {
+                    TargetPath = tempDir,
+                    TargetUrl = mainRepositoryFixture.RepositoryPath,
+                    CommitId = commitId
+                };
+
+                var gitPreparer = new GitPreparer(arguments.TargetUrl, arguments.DynamicRepositoryLocation, arguments.Authentication, arguments.TargetBranch, arguments.NoFetch, arguments.TargetPath);
+                gitPreparer.Initialise(true);
+
+                Assert.Throws<Exception>(() => gitPreparer.Initialise(true));
+            }
+        }
+        finally
+        {
+            Directory.Delete(tempDir, true);
+        }
+    }
+
     // TODO test around normalisation
-}
\ No newline at end of file
+}