diff --git a/builtin/sparse-checkout.c b/builtin/sparse-checkout.c
index a55c60d759..aa81199f85 100644
--- a/builtin/sparse-checkout.c
+++ b/builtin/sparse-checkout.c
@@ -112,7 +112,9 @@ static int update_working_directory(struct pattern_list *pl)
 
 	repo_hold_locked_index(r, &lock_file, LOCK_DIE_ON_ERROR);
 
+	setup_unpack_trees_porcelain(&o, "sparse-checkout");
 	result = update_sparsity(&o);
+	clear_unpack_trees_porcelain(&o);
 
 	if (result == UPDATE_SPARSITY_WARNINGS)
 		/*
diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh
index a991e0a80d..9bc65d32f0 100755
--- a/t/t1091-sparse-checkout-builtin.sh
+++ b/t/t1091-sparse-checkout-builtin.sh
@@ -328,12 +328,10 @@ test_expect_success 'sparse-checkout (init|set|disable) warns with dirty status'
 	echo dirty >dirty/folder1/a &&
 
 	git -C dirty sparse-checkout init 2>err &&
-	test_i18ngrep "error" err &&
-	test_i18ngrep "Cannot update sparse checkout" err &&
+	test_i18ngrep "error.*Cannot update sparse checkout" err &&
 
 	git -C dirty sparse-checkout set /folder2/* /deep/deeper1/* 2>err &&
-	test_i18ngrep "error" err &&
-	test_i18ngrep "Cannot update sparse checkout" err &&
+	test_i18ngrep "error.*Cannot update sparse checkout" err &&
 	test_path_is_file dirty/folder1/a &&
 
 	git -C dirty sparse-checkout disable 2>err &&