diff --git a/GitTfs/Core/GitRepository.cs b/GitTfs/Core/GitRepository.cs
index 1f804065..5b83b9f6 100644
--- a/GitTfs/Core/GitRepository.cs
+++ b/GitTfs/Core/GitRepository.cs
@@ -408,10 +408,9 @@ namespace Sep.Git.Tfs.Core
 
         public string AssertValidBranchName(string gitBranchName)
         {
-            var newGitBranchName = CommandOneline("check-ref-format", "--branch", gitBranchName);
-            if (string.IsNullOrWhiteSpace(newGitBranchName) || newGitBranchName.IndexOf("fatal:") == 0)
+            if (!_repository.Refs.IsValidName("refs/heads/" + gitBranchName))
                 throw new GitTfsException("The name specified for the new git branch is not allowed. Choose another one!");
-            return newGitBranchName.Trim();
+            return gitBranchName;
         }
 
         public bool CreateBranch(string gitBranchName, string target)
diff --git a/lib/libgit2sharp b/lib/libgit2sharp
index c1743ba7..247ca1a3 160000
--- a/lib/libgit2sharp
+++ b/lib/libgit2sharp
@@ -1 +1 @@
-Subproject commit c1743ba7f9547f53d565222f628fbc7138a65973
+Subproject commit 247ca1a30cfb722b74ada4288bcca7293f59b87b