diff --git a/arraycontext/impl/pytato.py b/arraycontext/impl/pytato.py
index 739a92231300e18ac16581d17994e95c39f88183..93bf7e47fb6a0614dc82f6ca1702adfe1e076c1f 100644
--- a/arraycontext/impl/pytato.py
+++ b/arraycontext/impl/pytato.py
@@ -528,5 +528,8 @@ class PytatoArrayContext(ArrayContext):
 
         return pt.einsum(spec, *(preprocess_arg(arg) for arg in args))
 
+    def permits_inplace_modification(self):
+        return False
+
 
 # }}}