diff --git a/meshmode/discretization/connection/refinement.py b/meshmode/discretization/connection/refinement.py
index 75604ec05dd945cde45e0e6cdd55724f88083c3f..4477a9bfd0fdbf4e24659c059997e1e6156fb894 100644
--- a/meshmode/discretization/connection/refinement.py
+++ b/meshmode/discretization/connection/refinement.py
@@ -161,7 +161,9 @@ def make_refinement_connection(refiner, coarse_discr, group_factory):
 
     coarse_mesh = refiner.get_previous_mesh()
     fine_mesh = refiner.last_mesh
-    assert coarse_discr.mesh is coarse_mesh
+    if coarse_discr.mesh != coarse_mesh:
+        raise ValueError(
+            "course_discr must live on the same mesh given to the refiner!")
 
     from meshmode.discretization import Discretization
     fine_discr = Discretization(