diff --git a/xbout/load.py b/xbout/load.py
index 3a82a617..bd36497e 100644
--- a/xbout/load.py
+++ b/xbout/load.py
@@ -1031,7 +1031,11 @@ def _trim(ds, *, guards, keep_boundaries, nxpe, nype, is_restart):
         ):
             trimmed_ds = trimmed_ds.drop_vars(name)
 
-    to_drop = _BOUT_PER_PROC_VARIABLES
+    if ds["MYPE"] == 0:
+        # Keep per-process variables from the root process
+        to_drop = None
+    else:
+        to_drop = _BOUT_PER_PROC_VARIABLES
 
     return trimmed_ds.drop_vars(to_drop, errors="ignore")
 
diff --git a/xbout/plotting/plotfuncs.py b/xbout/plotting/plotfuncs.py
index e115d434..5f944c16 100644
--- a/xbout/plotting/plotfuncs.py
+++ b/xbout/plotting/plotfuncs.py
@@ -752,9 +752,9 @@ def create_or_update_plot(plot_objects=None, tind=None, this_save_as=None):
                                 X, Y, Z, scalars=data, vmin=vmin, vmax=vmax, **kwargs
                             )
                         else:
-                            plot_objects[
-                                region_name + str(i)
-                            ].mlab_source.scalars = data
+                            plot_objects[region_name + str(i)].mlab_source.scalars = (
+                                data
+                            )
 
                 if mayavi_view is not None:
                     mlab.view(*mayavi_view)
diff --git a/xbout/tests/test_against_collect.py b/xbout/tests/test_against_collect.py
index 5f22cf97..a1bf3da3 100644
--- a/xbout/tests/test_against_collect.py
+++ b/xbout/tests/test_against_collect.py
@@ -220,5 +220,4 @@ def test_new_collect_indexing_slice(self, tmp_path_factory):
 
 
 @pytest.mark.skip
-class test_speed_against_old_collect:
-    ...
+class test_speed_against_old_collect: ...
diff --git a/xbout/tests/test_load.py b/xbout/tests/test_load.py
index d8766236..bb4c917e 100644
--- a/xbout/tests/test_load.py
+++ b/xbout/tests/test_load.py
@@ -472,8 +472,7 @@ def test_combine_along_y(self, tmp_path_factory, bout_xyt_example_files):
         xrt.assert_identical(actual, fake)
 
     @pytest.mark.skip
-    def test_combine_along_t(self):
-        ...
+    def test_combine_along_t(self): ...
 
     @pytest.mark.parametrize(
         "bout_v5,metric_3D", [(False, False), (True, False), (True, True)]
@@ -623,8 +622,7 @@ def test_drop_vars(self, tmp_path_factory, bout_xyt_example_files):
         assert "n" in ds.keys()
 
     @pytest.mark.skip
-    def test_combine_along_tx(self):
-        ...
+    def test_combine_along_tx(self): ...
 
     def test_restarts(self):
         datapath = Path(__file__).parent.joinpath(
diff --git a/xbout/utils.py b/xbout/utils.py
index 32be7edc..66dd9593 100644
--- a/xbout/utils.py
+++ b/xbout/utils.py
@@ -167,12 +167,16 @@ def _1d_coord_from_spacing(spacing, dim, ds=None, *, origin_at=None):
             )
 
         point_to_use = {
-            spacing.metadata["bout_xdim"]: spacing.metadata.get("MXG", 0)
-            if spacing.metadata["keep_xboundaries"]
-            else 0,
-            spacing.metadata["bout_ydim"]: spacing.metadata.get("MYG", 0)
-            if spacing.metadata["keep_yboundaries"]
-            else 0,
+            spacing.metadata["bout_xdim"]: (
+                spacing.metadata.get("MXG", 0)
+                if spacing.metadata["keep_xboundaries"]
+                else 0
+            ),
+            spacing.metadata["bout_ydim"]: (
+                spacing.metadata.get("MYG", 0)
+                if spacing.metadata["keep_yboundaries"]
+                else 0
+            ),
             spacing.metadata["bout_zdim"]: spacing.metadata.get("MZG", 0),
         }