diff --git a/src/ICSharpCode.SharpZipLib/Tar/TarArchive.cs b/src/ICSharpCode.SharpZipLib/Tar/TarArchive.cs
index 4b373fb64..aa482cc06 100644
--- a/src/ICSharpCode.SharpZipLib/Tar/TarArchive.cs
+++ b/src/ICSharpCode.SharpZipLib/Tar/TarArchive.cs
@@ -658,8 +658,9 @@ private void ExtractEntry(string destDir, TarEntry entry, bool allowParentTraver
 			name = name.Replace('/', Path.DirectorySeparatorChar);
 
 			string destFile = Path.Combine(destDir, name);
+			var destFileDir = Path.GetDirectoryName(Path.GetFullPath(destFile)) ?? "";
 
-			if (!allowParentTraversal && !Path.GetFullPath(destFile).StartsWith(destDir, StringComparison.InvariantCultureIgnoreCase))
+			if (!allowParentTraversal && !destFileDir.StartsWith(destDir, StringComparison.InvariantCultureIgnoreCase))
 			{
 				throw new InvalidNameException("Parent traversal in paths is not allowed");
 			}