diff --git a/lib/iris/aux_factory.py b/lib/iris/aux_factory.py
index 729817adf9..fd3b25c00c 100644
--- a/lib/iris/aux_factory.py
+++ b/lib/iris/aux_factory.py
@@ -187,7 +187,7 @@ def _nd_bounds(self, coord, dims, ndim):
         # Transpose to be consistent with the Cube.
         sorted_pairs = sorted(enumerate(dims), key=lambda pair: pair[1])
         transpose_order = [pair[0] for pair in sorted_pairs] + [len(dims)]
-        bounds = coord.bounds
+        bounds = coord.core_bounds()
         if dims:
             bounds = bounds.transpose(transpose_order)