diff --git a/NoRM/Linq/MongoQueryProvider.cs b/NoRM/Linq/MongoQueryProvider.cs
index d52264a4..25378fea 100644
--- a/NoRM/Linq/MongoQueryProvider.cs
+++ b/NoRM/Linq/MongoQueryProvider.cs
@@ -76,7 +76,9 @@ IQueryable IQueryProvider.CreateQuery(Expression expression)
         S IQueryProvider.Execute<S>(Expression expression)
         {
             object result = ExecuteQuery<S>(expression);
-            return (S)Convert.ChangeType(result, typeof(S));
+            if (result is IConvertible)
+                return (S)Convert.ChangeType(result, typeof(S));
+            return (S)ExecuteQuery<S>(expression);
         }
 
         /// <summary>