diff --git a/repo-settings.c b/repo-settings.c
index fb76ee4c69ca7e..b11ce98a5499bf 100644
--- a/repo-settings.c
+++ b/repo-settings.c
@@ -87,7 +87,7 @@ void prepare_repo_settings(struct repository *r)
 	/* Boolean config or default, does not cascade (simple)  */
 	repo_cfg_bool(r, "pack.usesparse", &r->settings.pack_use_sparse, 1);
 	repo_cfg_bool(r, "core.multipackindex", &r->settings.core_multi_pack_index, 1);
-	repo_cfg_bool(r, "index.sparse", &r->settings.sparse_index, 0);
+	repo_cfg_bool(r, "index.sparse", &r->settings.sparse_index, 1);
 	repo_cfg_bool(r, "index.skiphash", &r->settings.index_skip_hash, r->settings.index_skip_hash);
 	repo_cfg_bool(r, "pack.readreverseindex", &r->settings.pack_read_reverse_index, 1);
 	repo_cfg_bool(r, "pack.usebitmapboundarytraversal",
diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh
index 96ed3e1d698815..376d3c6abc9c77 100755
--- a/t/perf/p2000-sparse-operations.sh
+++ b/t/perf/p2000-sparse-operations.sh
@@ -56,7 +56,7 @@ test_expect_success 'setup repo and indexes' '
 	git -c core.sparseCheckoutCone=true clone --branch=wide --sparse . full-v3 &&
 	(
 		cd full-v3 &&
-		git sparse-checkout init --cone &&
+		git sparse-checkout init --cone --no-sparse-index &&
 		git sparse-checkout set $SPARSE_CONE &&
 		git config index.version 3 &&
 		git update-index --index-version=3 &&
@@ -65,7 +65,7 @@ test_expect_success 'setup repo and indexes' '
 	git -c core.sparseCheckoutCone=true clone --branch=wide --sparse . full-v4 &&
 	(
 		cd full-v4 &&
-		git sparse-checkout init --cone &&
+		git sparse-checkout init --cone --no-sparse-index &&
 		git sparse-checkout set $SPARSE_CONE &&
 		git config index.version 4 &&
 		git update-index --index-version=4 &&
diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index 8a95adf4b50de6..f40b5914d70223 100755
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -155,6 +155,7 @@ init_repos () {
 	git -C sparse-index reset --hard &&
 
 	# initialize sparse-checkout definitions
+	git -C sparse-checkout config index.sparse false &&
 	git -C sparse-checkout sparse-checkout init --cone &&
 	git -C sparse-checkout sparse-checkout set deep &&
 	git -C sparse-index sparse-checkout init --cone --sparse-index &&
diff --git a/t/t7817-grep-sparse-checkout.sh b/t/t7817-grep-sparse-checkout.sh
index eb595645657fad..db3004c4fe71c0 100755
--- a/t/t7817-grep-sparse-checkout.sh
+++ b/t/t7817-grep-sparse-checkout.sh
@@ -49,7 +49,7 @@ test_expect_success 'setup' '
 		echo "text" >B/b &&
 		git add A B &&
 		git commit -m sub &&
-		git sparse-checkout init --cone &&
+		git sparse-checkout init --cone --no-sparse-index &&
 		git sparse-checkout set B
 	) &&