diff --git a/holoviews/core/data/iris.py b/holoviews/core/data/iris.py
index 48617428c7..2a9f0b10ef 100644
--- a/holoviews/core/data/iris.py
+++ b/holoviews/core/data/iris.py
@@ -153,9 +153,10 @@ def shape(cls, dataset, gridded=False):
 
     @classmethod
     def coords(cls, dataset, dim, ordered=False, expanded=False):
+        dim = dataset.get_dimension(dim, strict=True)
         if expanded:
-            return util.expand_grid_coords(dataset, dim)
-        data = dataset.data.coords(dim)[0].points
+            return util.expand_grid_coords(dataset, dim.name)
+        data = dataset.data.coords(dim.name)[0].points
         if ordered and np.all(data[1:] < data[:-1]):
             data = data[::-1]
         return data
diff --git a/holoviews/core/data/xarray.py b/holoviews/core/data/xarray.py
index 8ea3c7c004..7442d66806 100644
--- a/holoviews/core/data/xarray.py
+++ b/holoviews/core/data/xarray.py
@@ -257,7 +257,7 @@ def groupby(cls, dataset, dimensions, container_type, group_type, **kwargs):
 
     @classmethod
     def coords(cls, dataset, dimension, ordered=False, expanded=False, edges=False):
-        dim = dataset.get_dimension(dimension)
+        dim = dataset.get_dimension(dimension, strict=True)
         dim = dimension if dim is None else dim.name
         irregular = cls.irregular(dataset, dim)
         if irregular or expanded: