diff --git a/test/unit/communication/test_communicator_grid.cpp b/test/unit/communication/test_communicator_grid.cpp
index bfa0fb355e..edc65ceaa9 100644
--- a/test/unit/communication/test_communicator_grid.cpp
+++ b/test/unit/communication/test_communicator_grid.cpp
@@ -99,6 +99,7 @@ void check_rank_full_communicator(const CommunicatorGrid& grid) {
 
 class CommunicatorGridTest : public ::testing::TestWithParam<Ordering> {};
 
+// TODO: Remove this test once CommunicatorGrid becomes move-only.
 TEST_P(CommunicatorGridTest, Copy) {
   Communicator world(MPI_COMM_WORLD);