diff --git a/Duplicati/UnitTest/SVNCheckoutsTest.cs b/Duplicati/UnitTest/SVNCheckoutsTest.cs
index 038d65001..cb7e1746a 100644
--- a/Duplicati/UnitTest/SVNCheckoutsTest.cs
+++ b/Duplicati/UnitTest/SVNCheckoutsTest.cs
@@ -74,7 +74,7 @@ namespace Duplicati.UnitTest
         /// <param name="target">The target destination for the backups</param>
         public static void RunTest(string[] folders, Dictionary<string, string> options, string target)
         {
-            LogHelper log = new LogHelper("unittest-{0}.log", Library.Utility.Utility.SerializeDateTime(DateTime.Now));
+            LogHelper log = new LogHelper(string.Format("unittest-{0}.log", Library.Utility.Utility.SerializeDateTime(DateTime.Now)));
             Log.CurrentLog = log;
             Log.LogLevel = Duplicati.Library.Logging.LogMessageType.Profiling;