diff --git a/python/examples/7-explore-advanced.py b/python/examples/7-explore-advanced.py
index 16b8a2b24..3dbb1bbd4 100644
--- a/python/examples/7-explore-advanced.py
+++ b/python/examples/7-explore-advanced.py
@@ -143,7 +143,9 @@ def mace_off_tsne(frames, environments):
 # different mace calculator.
 
 
-def mace_mp0_tsne(frames, _environments):
+def mace_mp0_tsne(frames, environments):
+    if environments is not None:
+        raise ValueError("'environments' are not supported")
     # Initialise a mace-mp0 calculator
     descriptor_opt = {"model": "small", "device": "cpu", "default_dtype": "float64"}
     calculator = mace_mp(**descriptor_opt)