From 35c5658b81fd48ff884f42065d0bc6c9e6965990 Mon Sep 17 00:00:00 2001
From: Luca Heltai <luca.heltai@sissa.it>
Date: Tue, 20 Dec 2022 19:07:53 +0100
Subject: [PATCH] Fix constness.

---
 source/lac/petsc_parallel_block_sparse_matrix.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/source/lac/petsc_parallel_block_sparse_matrix.cc b/source/lac/petsc_parallel_block_sparse_matrix.cc
index 49911c8dee..4d0accae14 100644
--- a/source/lac/petsc_parallel_block_sparse_matrix.cc
+++ b/source/lac/petsc_parallel_block_sparse_matrix.cc
@@ -176,7 +176,7 @@ namespace PETScWrappers
       return block(0, 0).get_mpi_communicator();
     }
 
-    BlockSparseMatrix::operator Mat() const
+    BlockSparseMatrix::operator const Mat &() const
     {
       return petsc_nest_matrix;
     }
-- 
2.39.5