diff --git a/include/msksheet.cpp b/include/msksheet.cpp
index 0779e2c18..7618fd769 100755
--- a/include/msksheet.cpp
+++ b/include/msksheet.cpp
@@ -1004,7 +1004,17 @@ void TSpreadsheet::list_handler(XI_EVENT *xiev)
       _firstfocus = FALSE;                                                  
     } 
     else 
-      mask().set_focus_win(win(), FALSE);
+    {
+      TMask_field& prev = mask().focus_field();
+
+      if (prev.test_focus_change())
+        mask().set_focus_win(win(), FALSE);
+      else
+      {
+        xiev->refused = TRUE;
+        mask().set_focus();
+      }
+    }
     break;
   case XIE_OFF_LIST:
     on_idle();