diff --git a/qgrid/grid.py b/qgrid/grid.py
index 44887b25..71afe93f 100644
--- a/qgrid/grid.py
+++ b/qgrid/grid.py
@@ -482,7 +482,7 @@ def show_grid(data_frame,
         options.update(column_options)
         column_options = options
     if grid_options is None:
-        grid_options = defaults.grid_options
+        grid_options = defaults.grid_options.copy()
     else:
         options = defaults.grid_options.copy()
         options.update(grid_options)