diff --git a/grudge/execution.py b/grudge/execution.py
index dba0648d820581f0f47febc308370cfea93e4d97..3cd9aade269db123d3ce2f91bebe3ccc7f6ba321 100644
--- a/grudge/execution.py
+++ b/grudge/execution.py
@@ -501,9 +501,6 @@ class ExecutionMapper(mappers.Evaluator,
             for in_grp, out_grp in zip(in_discr.groups, out_discr.groups):
                 assert in_grp.nelements == out_grp.nelements
 
-                if in_grp.nelements == 0:
-                    continue
-
                 # Cache operator
                 cache_key = "diff_batch", in_grp, out_grp, tuple(insn.operators),\
                     field.entry_dtype