diff --git a/ViewModels/EditorViewModel.fs b/ViewModels/EditorViewModel.fs
index 353c4f3..042f4cd 100644
--- a/ViewModels/EditorViewModel.fs
+++ b/ViewModels/EditorViewModel.fs
@@ -89,8 +89,8 @@ type EditorViewModel(_gridid: int, ?parent: EditorViewModel, ?_gridsize: GridSiz
         let mutable hlid = 0
         let mutable rep = 1
         for cell in line.cells do
-            hlid <- Option.defaultValue hlid cell.hl_id
-            rep  <- Option.defaultValue 1 cell.repeat
+            hlid <- ValueOption.defaultValue hlid cell.hl_id
+            rep  <- ValueOption.defaultValue 1 cell.repeat
             for _i = 1 to rep do
                 m_gridbuffer.[row, col].hlid <- hlid
                 m_gridbuffer.[row, col].text <- cell.text
diff --git a/def.fs b/def.fs
index bd42703..20ee831 100644
--- a/def.fs
+++ b/def.fs
@@ -4,7 +4,6 @@ open FVim.log
 open FVim.common
 
 open Avalonia.Media
-open System.Collections.Generic
 open System
 
 let inline private trace fmt = trace "def" fmt
@@ -121,8 +120,8 @@ type Rune =
 type GridCell = 
     {
         text: Rune
-        hl_id: int option
-        repeat: int option
+        hl_id: int voption
+        repeat: int voption
     }
 
 [<Struct>]
@@ -511,11 +510,11 @@ let (|Rune|_|) (x:obj) =
 let parse_grid_cell (x: obj) =
     match x with
     | ObjArray [| (Rune txt) |] 
-        -> Some { text = txt; hl_id = None; repeat = None}
+        -> Some { text = txt; hl_id = ValueNone; repeat = ValueNone}
     | ObjArray [| (Rune txt); (Integer32 hl_id) |] 
-        -> Some { text = txt; hl_id = Some hl_id; repeat = None}
+        -> Some { text = txt; hl_id = ValueSome hl_id; repeat = ValueNone}
     | ObjArray [| (Rune txt); (Integer32 hl_id); (Integer32 repeat) |] 
-        -> Some { text = txt; hl_id = Some hl_id; repeat = Some repeat}
+        -> Some { text = txt; hl_id = ValueSome hl_id; repeat = ValueSome repeat}
     | _ -> None
 
 let parse_grid_line (x: obj) =