diff --git a/Documentation/config/feature.txt b/Documentation/config/feature.txt
index 95975e50912c6f..f0e1d4cb2be18e 100644
--- a/Documentation/config/feature.txt
+++ b/Documentation/config/feature.txt
@@ -23,6 +23,9 @@ feature.manyFiles::
 	working directory. With many files, commands such as `git status` and
 	`git checkout` may be slow and these new defaults improve performance:
 +
+* `index.skipHash=true` speeds up index writes by not computing a trailing
+  checksum.
++
 * `index.version=4` enables path-prefix compression in the index.
 +
 * `core.untrackedCache=true` enables the untracked cache. This setting assumes
diff --git a/read-cache.c b/read-cache.c
index fb4d6fb6387e37..1844953fba7389 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -2923,12 +2923,13 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile,
 	int ieot_entries = 1;
 	struct index_entry_offset_table *ieot = NULL;
 	int nr, nr_threads;
-	int skip_hash;
 
 	f = hashfd(tempfile->fd, tempfile->filename.buf);
 
-	if (!git_config_get_maybe_bool("index.skiphash", &skip_hash))
-		f->skip_hash = skip_hash;
+	if (istate->repo) {
+		prepare_repo_settings(istate->repo);
+		f->skip_hash = istate->repo->settings.index_skip_hash;
+	}
 
 	for (i = removed = extended = 0; i < entries; i++) {
 		if (cache[i]->ce_flags & CE_REMOVE)
diff --git a/repo-settings.c b/repo-settings.c
index 3021921c53d22a..3dbd3f0e2ec33d 100644
--- a/repo-settings.c
+++ b/repo-settings.c
@@ -47,6 +47,7 @@ void prepare_repo_settings(struct repository *r)
 	}
 	if (manyfiles) {
 		r->settings.index_version = 4;
+		r->settings.index_skip_hash = 1;
 		r->settings.core_untracked_cache = UNTRACKED_CACHE_WRITE;
 	}
 
@@ -61,6 +62,7 @@ void prepare_repo_settings(struct repository *r)
 	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.skiphash", &r->settings.index_skip_hash, r->settings.index_skip_hash);
 
 	/*
 	 * The GIT_TEST_MULTI_PACK_INDEX variable is special in that
diff --git a/repository.h b/repository.h
index 6c461c5b9def01..e8c67ffe165424 100644
--- a/repository.h
+++ b/repository.h
@@ -42,6 +42,7 @@ struct repo_settings {
 	struct fsmonitor_settings *fsmonitor; /* lazily loaded */
 
 	int index_version;
+	int index_skip_hash;
 	enum untracked_cache_setting core_untracked_cache;
 
 	int pack_use_sparse;
diff --git a/scalar.c b/scalar.c
index 6c52243cdf1f68..b49bb8c24ec74d 100644
--- a/scalar.c
+++ b/scalar.c
@@ -143,6 +143,7 @@ static int set_recommended_config(int reconfigure)
 		{ "credential.validate", "false", 1 }, /* GCM4W-only */
 		{ "gc.auto", "0", 1 },
 		{ "gui.GCWarning", "false", 1 },
+		{ "index.skipHash", "false", 1 },
 		{ "index.threads", "true", 1 },
 		{ "index.version", "4", 1 },
 		{ "merge.stat", "false", 1 },
diff --git a/t/t1600-index.sh b/t/t1600-index.sh
index 55816756607016..be0a0a8a008530 100755
--- a/t/t1600-index.sh
+++ b/t/t1600-index.sh
@@ -72,7 +72,18 @@ test_expect_success 'index.skipHash config option' '
 		test_trailing_hash .git/index >hash &&
 		echo $(test_oid zero) >expect &&
 		test_cmp expect hash &&
-		git fsck
+		git fsck &&
+
+		rm -f .git/index &&
+		git -c feature.manyFiles=true add a &&
+		test_trailing_hash .git/index >hash &&
+		test_cmp expect hash &&
+
+		rm -f .git/index &&
+		git -c feature.manyFiles=true \
+		    -c index.skipHash=false add a &&
+		test_trailing_hash .git/index >hash &&
+		! test_cmp expect hash
 	)
 '