diff --git a/xbout/geometries.py b/xbout/geometries.py
index 6774c4fa..fa8a67b6 100644
--- a/xbout/geometries.py
+++ b/xbout/geometries.py
@@ -194,7 +194,14 @@ def apply_geometry(ds, geometry_name, *, coordinates=None, grid=None):
         can_use_1d_z_coord = (nz == 1) or use_metric_3d
 
         if can_use_1d_z_coord:
-            z = _1d_coord_from_spacing(updated_ds["dz"], zcoord, updated_ds)
+            if updated_ds.geometry == "fci":
+                # dz is varying. just set to a linspace
+                z = xr.DataArray(
+                    np.linspace(start=0, stop=2 * np.pi, num=nz, endpoint=False),
+                    dims=zcoord,
+                )
+            else:
+                z = _1d_coord_from_spacing(updated_ds["dz"], zcoord, updated_ds)
         else:
             if bout_v5:
                 if not np.all(updated_ds["dz"].min() == updated_ds["dz"].max()):
diff --git a/xbout/plotting/utils.py b/xbout/plotting/utils.py
index a7fa7eda..0c09226e 100644
--- a/xbout/plotting/utils.py
+++ b/xbout/plotting/utils.py
@@ -64,6 +64,8 @@ def plot_separatrix(da, sep_pos, ax, radial_coord="x"):
 
 def _decompose_regions(da):
 
+    if da.geometry == "fci":
+        return {region: da for region in da.bout._regions}
     return {
         region: da.bout.from_region(region, with_guards=1)
         for region in da.bout._regions