diff --git a/python-package/lets_plot/__init__.py b/python-package/lets_plot/__init__.py
index 1f9a3c43b48..8abb5f70258 100644
--- a/python-package/lets_plot/__init__.py
+++ b/python-package/lets_plot/__init__.py
@@ -171,6 +171,10 @@ def set_theme(cls, theme: Union['core.FeatureSpec', 'core.FeatureSpecArray']):
             Theme spec provided by `theme(...)`, `theme_xxx()`, `flavor_xxx()` functions, or their sum.
 
         """
+        if theme is None:
+            _set_global_theme(None)
+            return
+
         if theme.kind != 'theme' and not (theme.kind == 'feature-list' and all(f.kind == 'theme' for f in theme)):
             raise ValueError("Only `theme(...)`, `theme_xxx()`, `flavor_xxx()`, or a sum of them are supported")
 
diff --git a/python-package/lets_plot/plot/gggrid_.py b/python-package/lets_plot/plot/gggrid_.py
index 12e1aa0f7ca..ab2fd22f724 100644
--- a/python-package/lets_plot/plot/gggrid_.py
+++ b/python-package/lets_plot/plot/gggrid_.py
@@ -119,7 +119,7 @@ def gggrid(plots: list, ncol: int = None, *,
 
     def _strip_theme_if_global(fig):
         # Strip global theme options from plots in grid (see issue: #966).
-        if global_theme_options is not None and fig is not None and 'theme' in fig.props() and fig.props()['theme'] == global_theme_options:
+        if global_theme_options is not None and fig is not None and 'theme' in fig.props() and fig.props()['theme'] == global_theme_options.props():
             if isinstance(fig, PlotSpec):
                 fig = PlotSpec.duplicate(fig)
                 fig.props().pop('theme')
diff --git a/python-package/test/plot/test_gggrid_theme.py b/python-package/test/plot/test_gggrid_theme.py
index 5b10e57cbd0..fa9fa42480a 100644
--- a/python-package/test/plot/test_gggrid_theme.py
+++ b/python-package/test/plot/test_gggrid_theme.py
@@ -6,8 +6,6 @@
 
 import lets_plot as gg
 
-from lets_plot._global_settings import PLOT_THEME
-
 
 def test_gggrid_theme():
     spec = gg.gggrid([gg.ggplot()]) + gg.theme_grey()
@@ -43,9 +41,9 @@ def test_gggrid_global_theme_override():
         spec = gg.gggrid([gg.ggplot()]) + gg.theme_light()
     finally:
         # Clear global setting
-        gg.LetsPlot.set({
-            PLOT_THEME: None
-        })
+        gg.LetsPlot.set_theme(
+            None
+        )
 
     assert 'theme' in spec.as_dict()
     assert spec.as_dict()['theme'] == {'name': 'light'}
@@ -67,9 +65,9 @@ def test_gggrid_global_theme_override_cancelled():
         spec = gg.gggrid([fig]) + gg.theme_light()
     finally:
         # Clear global setting
-        gg.LetsPlot.set({
-            PLOT_THEME: None
-        })
+        gg.LetsPlot.set_theme(
+            None
+        )
 
     assert 'theme' in spec.as_dict()
     assert spec.as_dict()['theme'] == {'name': 'light'}