diff --git a/builtin/fast-import.c b/builtin/fast-import.c
index 1c85eafe43..1bf50a73dc 100644
--- a/builtin/fast-import.c
+++ b/builtin/fast-import.c
@@ -739,7 +739,6 @@ static void start_packfile(void)
 {
 	struct strbuf tmp_file = STRBUF_INIT;
 	struct packed_git *p;
-	struct pack_header hdr;
 	int pack_fd;
 
 	pack_fd = odb_mkstemp(&tmp_file, "pack/tmp_pack_XXXXXX");
@@ -750,13 +749,8 @@ static void start_packfile(void)
 	p->do_not_close = 1;
 	pack_file = hashfd(pack_fd, p->pack_name);
 
-	hdr.hdr_signature = htonl(PACK_SIGNATURE);
-	hdr.hdr_version = htonl(2);
-	hdr.hdr_entries = 0;
-	hashwrite(pack_file, &hdr, sizeof(hdr));
-
 	pack_data = p;
-	pack_size = sizeof(hdr);
+	pack_size = write_pack_header(pack_file, 0);
 	object_count = 0;
 
 	REALLOC_ARRAY(all_packs, pack_id + 1);
diff --git a/midx.c b/midx.c
index cc19b66152..0de42ffdfb 100644
--- a/midx.c
+++ b/midx.c
@@ -432,14 +432,11 @@ static size_t write_midx_header(struct hashfile *f,
 				unsigned char num_chunks,
 				uint32_t num_packs)
 {
-	unsigned char byte_values[4];
-
 	hashwrite_be32(f, MIDX_SIGNATURE);
-	byte_values[0] = MIDX_VERSION;
-	byte_values[1] = oid_version();
-	byte_values[2] = num_chunks;
-	byte_values[3] = 0; /* unused */
-	hashwrite(f, byte_values, sizeof(byte_values));
+	hashwrite_u8(f, MIDX_VERSION);
+	hashwrite_u8(f, oid_version());
+	hashwrite_u8(f, num_chunks);
+	hashwrite_u8(f, 0); /* unused */
 	hashwrite_be32(f, num_packs);
 
 	return MIDX_HEADER_SIZE;
diff --git a/pack-bitmap-write.c b/pack-bitmap-write.c
index a7a4964b50..5e998bdaa7 100644
--- a/pack-bitmap-write.c
+++ b/pack-bitmap-write.c
@@ -503,8 +503,7 @@ static void write_hash_cache(struct hashfile *f,
 
 	for (i = 0; i < index_nr; ++i) {
 		struct object_entry *entry = (struct object_entry *)index[i];
-		uint32_t hash_value = htonl(entry->hash);
-		hashwrite(f, &hash_value, sizeof(hash_value));
+		hashwrite_be32(f, entry->hash);
 	}
 }