diff --git a/grudge/array_context.py b/grudge/array_context.py
index 01949935..45f7d8ef 100644
--- a/grudge/array_context.py
+++ b/grudge/array_context.py
@@ -609,7 +609,7 @@ def get_reasonable_array_context_class(
         fusion = lazy
 
     if numpy:
-        assert not lazy
+        assert not (lazy or fusion)
         if distributed:
             actx_class = MPINumpyArrayContext
         else: