diff --git a/Providers/XBaseFileProvider.cs b/Providers/XBaseFileProvider.cs
index 4b54dc0..1a07f95 100644
--- a/Providers/XBaseFileProvider.cs
+++ b/Providers/XBaseFileProvider.cs
@@ -913,7 +913,7 @@ namespace xFileService.Providers
         private int GetLastIndex(TKey providedForId)
         {
             //
-            var result = 0;
+            var result = -1;
 
             //
             // Validate ...
@@ -935,7 +935,7 @@ namespace xFileService.Providers
                 .AsEnumerable();
             if (all.IsNull() || !all.HasChild())
             {
-                result = 0;
+                result = -1;
             }
             else
             {
@@ -950,7 +950,7 @@ namespace xFileService.Providers
                 }
                 else
                 {
-                    result = 0;
+                    result = -1;
                 }
             }