diff --git a/midx-write.c b/midx-write.c
index 1bc2f5256916e69924245951f654c1047ffeab84..bcd1d50eb0f5c292c904a38f13279b1ebec9c855 100644
--- a/midx-write.c
+++ b/midx-write.c
@@ -991,9 +991,10 @@ static int link_midx_to_chain(struct multi_pack_index *m)
 	for (i = 0; i < ARRAY_SIZE(midx_exts); i++) {
 		const unsigned char *hash = get_midx_checksum(m);
 
-		get_midx_filename_ext(&from, m->object_dir, hash,
-				      midx_exts[i].non_split);
-		get_split_midx_filename_ext(&to, m->object_dir, hash,
+		get_midx_filename_ext(m->repo->hash_algo, &from, m->object_dir,
+				      hash, midx_exts[i].non_split);
+		get_split_midx_filename_ext(m->repo->hash_algo, &to,
+					    m->object_dir, hash,
 					    midx_exts[i].split);
 
 		if (link(from.buf, to.buf) < 0 && errno != ENOENT) {
@@ -1012,9 +1013,8 @@ static int link_midx_to_chain(struct multi_pack_index *m)
 	return ret;
 }
 
-static void clear_midx_files(const char *object_dir,
-			     const char **hashes,
-			     uint32_t hashes_nr,
+static void clear_midx_files(struct repository *r, const char *object_dir,
+			     const char **hashes, uint32_t hashes_nr,
 			     unsigned incremental)
 {
 	/*
@@ -1039,7 +1039,7 @@ static void clear_midx_files(const char *object_dir,
 	}
 
 	if (incremental)
-		get_midx_filename(&buf, object_dir);
+		get_midx_filename(r->hash_algo, &buf, object_dir);
 	else
 		get_midx_chain_filename(&buf, object_dir);
 
@@ -1083,7 +1083,7 @@ static int write_midx_internal(struct repository *r, const char *object_dir,
 			    "%s/pack/multi-pack-index.d/tmp_midx_XXXXXX",
 			    object_dir);
 	else
-		get_midx_filename(&midx_name, object_dir);
+		get_midx_filename(r->hash_algo, &midx_name, object_dir);
 	if (safe_create_leading_directories(midx_name.buf))
 		die_errno(_("unable to create leading directories of %s"),
 			  midx_name.buf);
@@ -1440,8 +1440,8 @@ static int write_midx_internal(struct repository *r, const char *object_dir,
 		if (link_midx_to_chain(ctx.base_midx) < 0)
 			return -1;
 
-		get_split_midx_filename_ext(&final_midx_name, object_dir,
-					    midx_hash, MIDX_EXT_MIDX);
+		get_split_midx_filename_ext(r->hash_algo, &final_midx_name,
+					    object_dir, midx_hash, MIDX_EXT_MIDX);
 
 		if (rename_tempfile(&incr, final_midx_name.buf) < 0) {
 			error_errno(_("unable to rename new multi-pack-index layer"));
@@ -1474,7 +1474,7 @@ static int write_midx_internal(struct repository *r, const char *object_dir,
 	if (commit_lock_file(&lk) < 0)
 		die_errno(_("could not write multi-pack-index"));
 
-	clear_midx_files(object_dir, keep_hashes,
+	clear_midx_files(r, object_dir, keep_hashes,
 			 ctx.num_multi_pack_indexes_before + 1,
 			 ctx.incremental);
 
diff --git a/midx.c b/midx.c
index 98ee84d4a8bf388906634ad695ff39acdaa2c6d5..f45ea842cd6eda23d2eadc9deaae43839aef24c1 100644
--- a/midx.c
+++ b/midx.c
@@ -28,17 +28,19 @@ const unsigned char *get_midx_checksum(struct multi_pack_index *m)
 	return m->data + m->data_len - m->repo->hash_algo->rawsz;
 }
 
-void get_midx_filename(struct strbuf *out, const char *object_dir)
+void get_midx_filename(const struct git_hash_algo *hash_algo,
+		       struct strbuf *out, const char *object_dir)
 {
-	get_midx_filename_ext(out, object_dir, NULL, NULL);
+	get_midx_filename_ext(hash_algo, out, object_dir, NULL, NULL);
 }
 
-void get_midx_filename_ext(struct strbuf *out, const char *object_dir,
+void get_midx_filename_ext(const struct git_hash_algo *hash_algo,
+			   struct strbuf *out, const char *object_dir,
 			   const unsigned char *hash, const char *ext)
 {
 	strbuf_addf(out, "%s/pack/multi-pack-index", object_dir);
 	if (ext)
-		strbuf_addf(out, "-%s.%s", hash_to_hex(hash), ext);
+		strbuf_addf(out, "-%s.%s", hash_to_hex_algop(hash, hash_algo), ext);
 }
 
 static int midx_read_oid_fanout(const unsigned char *chunk_start,
@@ -234,11 +236,13 @@ void get_midx_chain_filename(struct strbuf *buf, const char *object_dir)
 	strbuf_addstr(buf, "/multi-pack-index-chain");
 }
 
-void get_split_midx_filename_ext(struct strbuf *buf, const char *object_dir,
+void get_split_midx_filename_ext(const struct git_hash_algo *hash_algo,
+				 struct strbuf *buf, const char *object_dir,
 				 const unsigned char *hash, const char *ext)
 {
 	get_midx_chain_dirname(buf, object_dir);
-	strbuf_addf(buf, "/multi-pack-index-%s.%s", hash_to_hex(hash), ext);
+	strbuf_addf(buf, "/multi-pack-index-%s.%s",
+		    hash_to_hex_algop(hash, hash_algo), ext);
 }
 
 static int open_multi_pack_index_chain(const struct git_hash_algo *hash_algo,
@@ -326,8 +330,8 @@ static struct multi_pack_index *load_midx_chain_fd_st(struct repository *r,
 		valid = 0;
 
 		strbuf_reset(&buf);
-		get_split_midx_filename_ext(&buf, object_dir, layer.hash,
-					    MIDX_EXT_MIDX);
+		get_split_midx_filename_ext(r->hash_algo, &buf, object_dir,
+					    layer.hash, MIDX_EXT_MIDX);
 		m = load_multi_pack_index_one(r, object_dir, buf.buf, local);
 
 		if (m) {
@@ -379,7 +383,7 @@ struct multi_pack_index *load_multi_pack_index(struct repository *r,
 	struct strbuf midx_name = STRBUF_INIT;
 	struct multi_pack_index *m;
 
-	get_midx_filename(&midx_name, object_dir);
+	get_midx_filename(r->hash_algo, &midx_name, object_dir);
 
 	m = load_multi_pack_index_one(r, object_dir,
 				      midx_name.buf, local);
@@ -822,7 +826,7 @@ void clear_midx_file(struct repository *r)
 {
 	struct strbuf midx = STRBUF_INIT;
 
-	get_midx_filename(&midx, r->objects->odb->path);
+	get_midx_filename(r->hash_algo, &midx, r->objects->odb->path);
 
 	if (r->objects && r->objects->multi_pack_index) {
 		close_midx(r->objects->multi_pack_index);
@@ -891,7 +895,7 @@ int verify_midx_file(struct repository *r, const char *object_dir, unsigned flag
 		struct stat sb;
 		struct strbuf filename = STRBUF_INIT;
 
-		get_midx_filename(&filename, object_dir);
+		get_midx_filename(r->hash_algo, &filename, object_dir);
 
 		if (!stat(filename.buf, &sb)) {
 			error(_("multi-pack-index file exists, but failed to parse"));
diff --git a/midx.h b/midx.h
index 78efa28d35371795fa33c68660278182debb60ab..9d1374cbd58d016bb82338337b2a4e5ba7234092 100644
--- a/midx.h
+++ b/midx.h
@@ -7,6 +7,7 @@ struct object_id;
 struct pack_entry;
 struct repository;
 struct bitmapped_pack;
+struct git_hash_algo;
 
 #define MIDX_SIGNATURE 0x4d494458 /* "MIDX" */
 #define MIDX_VERSION 1
@@ -89,12 +90,15 @@ struct multi_pack_index {
 #define MIDX_EXT_MIDX "midx"
 
 const unsigned char *get_midx_checksum(struct multi_pack_index *m);
-void get_midx_filename(struct strbuf *out, const char *object_dir);
-void get_midx_filename_ext(struct strbuf *out, const char *object_dir,
+void get_midx_filename(const struct git_hash_algo *hash_algo,
+		       struct strbuf *out, const char *object_dir);
+void get_midx_filename_ext(const struct git_hash_algo *hash_algo,
+			   struct strbuf *out, const char *object_dir,
 			   const unsigned char *hash, const char *ext);
 void get_midx_chain_dirname(struct strbuf *buf, const char *object_dir);
 void get_midx_chain_filename(struct strbuf *buf, const char *object_dir);
-void get_split_midx_filename_ext(struct strbuf *buf, const char *object_dir,
+void get_split_midx_filename_ext(const struct git_hash_algo *hash_algo,
+				 struct strbuf *buf, const char *object_dir,
 				 const unsigned char *hash, const char *ext);
 
 struct multi_pack_index *load_multi_pack_index(struct repository *r,
diff --git a/pack-bitmap.c b/pack-bitmap.c
index 0cb1b56c9d5a55936ba53e2ff904ffe46cdcbafc..7b62d099cab5729a60a36b3ad15276fdc351aa97 100644
--- a/pack-bitmap.c
+++ b/pack-bitmap.c
@@ -375,8 +375,8 @@ static int load_bitmap_entries_v1(struct bitmap_index *index)
 char *midx_bitmap_filename(struct multi_pack_index *midx)
 {
 	struct strbuf buf = STRBUF_INIT;
-	get_midx_filename_ext(&buf, midx->object_dir, get_midx_checksum(midx),
-			      MIDX_EXT_BITMAP);
+	get_midx_filename_ext(midx->repo->hash_algo, &buf, midx->object_dir,
+			      get_midx_checksum(midx), MIDX_EXT_BITMAP);
 
 	return strbuf_detach(&buf, NULL);
 }
@@ -415,7 +415,7 @@ static int open_midx_bitmap_1(struct bitmap_index *bitmap_git,
 
 	if (bitmap_git->pack || bitmap_git->midx) {
 		struct strbuf buf = STRBUF_INIT;
-		get_midx_filename(&buf, midx->object_dir);
+		get_midx_filename(midx->repo->hash_algo, &buf, midx->object_dir);
 		trace2_data_string("bitmap", bitmap_repo(bitmap_git),
 				   "ignoring extra midx bitmap file", buf.buf);
 		close(fd);
diff --git a/pack-revindex.c b/pack-revindex.c
index 22d3c2346488de6279b6f26a69fe611106c1365a..d3832478d99edffae17db0bbe85aa981c1a3ad30 100644
--- a/pack-revindex.c
+++ b/pack-revindex.c
@@ -383,7 +383,7 @@ int load_midx_revindex(struct multi_pack_index *m)
 	trace2_data_string("load_midx_revindex", the_repository,
 			   "source", "rev");
 
-	get_midx_filename_ext(&revindex_name, m->object_dir,
+	get_midx_filename_ext(m->repo->hash_algo, &revindex_name, m->object_dir,
 			      get_midx_checksum(m), MIDX_EXT_REV);
 
 	ret = load_revindex_from_disk(revindex_name.buf,
