diff --git a/src/ce_optionseditor.lfm b/src/ce_optionseditor.lfm
index 3b050c93..5922b1d1 100644
--- a/src/ce_optionseditor.lfm
+++ b/src/ce_optionseditor.lfm
@@ -7,6 +7,7 @@ inherited CEOptionEditorWidget: TCEOptionEditorWidget
   Caption = 'Options editor'
   ClientHeight = 493
   ClientWidth = 559
+  OnCloseQuery = FormCloseQuery
   inherited Back: TPanel
     Height = 493
     Width = 559
diff --git a/src/ce_optionseditor.pas b/src/ce_optionseditor.pas
index 8666407b..d7fefbaa 100644
--- a/src/ce_optionseditor.pas
+++ b/src/ce_optionseditor.pas
@@ -33,6 +33,7 @@ type
     selCat: TTreeView;
     procedure btnAcceptClick(Sender: TObject);
     procedure btnCancelClick(Sender: TObject);
+    procedure FormCloseQuery(Sender: TObject; var CanClose: boolean);
     procedure inspectorEditorFilter(Sender: TObject; aEditor: TPropertyEditor;
       var aShow: boolean);
     procedure inspectorModified(Sender: TObject);
@@ -204,6 +205,20 @@ begin
     .optionedEvent(oeeCancel);
 end;
 
+procedure TCEOptionEditorWidget.FormCloseQuery(Sender: TObject;
+  var CanClose: boolean);
+begin
+  if fCatChanged then
+  begin
+    CanClose := dlgOkCancel(
+       'The modifications of the current category are not validated, ' +
+       'discard them and continue ?' ) = mrOk;
+    if CanClose then
+      btnCancelClick(nil);
+  end
+  else CanClose := true;
+end;
+
 procedure TCEOptionEditorWidget.inspectorEditorFilter(Sender: TObject;aEditor:
   TPropertyEditor; var aShow: boolean);
 begin