diff --git a/covjsonkit/decoder/BoundingBox.py b/covjsonkit/decoder/BoundingBox.py
index 6dafcb7..9e0e3e6 100644
--- a/covjsonkit/decoder/BoundingBox.py
+++ b/covjsonkit/decoder/BoundingBox.py
@@ -84,9 +84,9 @@ def to_xarray(self):
                     coverage["mars:metadata"]["step"]
                 ] = coverage["ranges"][parameter]["values"]
 
-        datetimes = list(set(datetimes))
-        numbers = list(set(numbers))
-        steps = list(set(steps))
+        datetimes = sorted(list(set(datetimes)))
+        numbers = sorted(list(set(numbers)))
+        steps = sorted(list(set(steps)))
 
         new_values = {}
         for parameter in values.keys():