diff --git a/object-file.c b/object-file.c
index 65e730684b..c0f896673b 100644
--- a/object-file.c
+++ b/object-file.c
@@ -409,6 +409,7 @@ static int read_object_info_from_path(struct odb_source *source,
 	char hdr[MAX_HEADER_LEN];
 	unsigned long size_scratch;
 	enum object_type type_scratch;
+	struct stat st;
 
 	/*
 	 * If we don't care about type or size, then we don't
@@ -421,7 +422,7 @@ static int read_object_info_from_path(struct odb_source *source,
 	if (!oi || (!oi->typep && !oi->sizep && !oi->contentp)) {
 		struct stat st;
 
-		if ((!oi || !oi->disk_sizep) && (flags & OBJECT_INFO_QUICK)) {
+		if ((!oi || (!oi->disk_sizep && !oi->mtimep)) && (flags & OBJECT_INFO_QUICK)) {
 			ret = quick_has_loose(source->loose, oid) ? 0 : -1;
 			goto out;
 		}
@@ -431,8 +432,12 @@ static int read_object_info_from_path(struct odb_source *source,
 			goto out;
 		}
 
-		if (oi && oi->disk_sizep)
-			*oi->disk_sizep = st.st_size;
+		if (oi) {
+			if (oi->disk_sizep)
+				*oi->disk_sizep = st.st_size;
+			if (oi->mtimep)
+				*oi->mtimep = st.st_mtime;
+		}
 
 		ret = 0;
 		goto out;
@@ -446,7 +451,21 @@ static int read_object_info_from_path(struct odb_source *source,
 		goto out;
 	}
 
-	map = map_fd(fd, path, &mapsize);
+	if (fstat(fd, &st)) {
+		close(fd);
+		ret = -1;
+		goto out;
+	}
+
+	mapsize = xsize_t(st.st_size);
+	if (!mapsize) {
+		close(fd);
+		ret = error(_("object file %s is empty"), path);
+		goto out;
+	}
+
+	map = xmmap(NULL, mapsize, PROT_READ, MAP_PRIVATE, fd, 0);
+	close(fd);
 	if (!map) {
 		ret = -1;
 		goto out;
@@ -454,6 +473,8 @@ static int read_object_info_from_path(struct odb_source *source,
 
 	if (oi->disk_sizep)
 		*oi->disk_sizep = mapsize;
+	if (oi->mtimep)
+		*oi->mtimep = st.st_mtime;
 
 	stream_to_end = &stream;
 
diff --git a/odb.c b/odb.c
index 65f0447aa5..67decd3908 100644
--- a/odb.c
+++ b/odb.c
@@ -702,6 +702,8 @@ static int do_oid_object_info_extended(struct object_database *odb,
 				oidclr(oi->delta_base_oid, odb->repo->hash_algo);
 			if (oi->contentp)
 				*oi->contentp = xmemdupz(co->buf, co->size);
+			if (oi->mtimep)
+				*oi->mtimep = 0;
 			oi->whence = OI_CACHED;
 		}
 		return 0;
diff --git a/odb.h b/odb.h
index 8f6d95aee5..9e22f79172 100644
--- a/odb.h
+++ b/odb.h
@@ -317,6 +317,7 @@ struct object_info {
 	off_t *disk_sizep;
 	struct object_id *delta_base_oid;
 	void **contentp;
+	time_t *mtimep;
 
 	/* Response */
 	enum {
diff --git a/packfile.c b/packfile.c
index 4f84bc19d9..c96ec21f86 100644
--- a/packfile.c
+++ b/packfile.c
@@ -1578,13 +1578,14 @@ static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
 	hashmap_add(&delta_base_cache, &ent->ent);
 }
 
-int packed_object_info(struct packed_git *p,
-		       off_t obj_offset, struct object_info *oi)
+static int packed_object_info_with_index_pos(struct packed_git *p, off_t obj_offset,
+					     uint32_t *maybe_index_pos, struct object_info *oi)
 {
 	struct pack_window *w_curs = NULL;
 	unsigned long size;
 	off_t curpos = obj_offset;
 	enum object_type type = OBJ_NONE;
+	uint32_t pack_pos;
 	int ret;
 
 	/*
@@ -1619,16 +1620,34 @@ int packed_object_info(struct packed_git *p,
 		}
 	}
 
-	if (oi->disk_sizep) {
-		uint32_t pos;
-		if (offset_to_pack_pos(p, obj_offset, &pos) < 0) {
+	if (oi->disk_sizep || (oi->mtimep && p->is_cruft)) {
+		if (offset_to_pack_pos(p, obj_offset, &pack_pos) < 0) {
 			error("could not find object at offset %"PRIuMAX" "
 			      "in pack %s", (uintmax_t)obj_offset, p->pack_name);
 			ret = -1;
 			goto out;
 		}
+	}
 
-		*oi->disk_sizep = pack_pos_to_offset(p, pos + 1) - obj_offset;
+	if (oi->disk_sizep)
+		*oi->disk_sizep = pack_pos_to_offset(p, pack_pos + 1) - obj_offset;
+
+	if (oi->mtimep) {
+		if (p->is_cruft) {
+			uint32_t index_pos;
+
+			if (load_pack_mtimes(p) < 0)
+				die(_("could not load cruft pack .mtimes"));
+
+			if (maybe_index_pos)
+				index_pos = *maybe_index_pos;
+			else
+				index_pos = pack_pos_to_index(p, pack_pos);
+
+			*oi->mtimep = nth_packed_mtime(p, index_pos);
+		} else {
+			*oi->mtimep = p->mtime;
+		}
 	}
 
 	if (oi->typep) {
@@ -1681,6 +1700,12 @@ out:
 	return ret;
 }
 
+int packed_object_info(struct packed_git *p, off_t obj_offset,
+		       struct object_info *oi)
+{
+	return packed_object_info_with_index_pos(p, obj_offset, NULL, oi);
+}
+
 static void *unpack_compressed_entry(struct packed_git *p,
 				    struct pack_window **w_curs,
 				    off_t curpos,
@@ -2377,7 +2402,8 @@ static int packfile_store_for_each_object_wrapper(const struct object_id *oid,
 	if (data->oi) {
 		off_t offset = nth_packed_object_offset(pack, index_pos);
 
-		if (packed_object_info(pack, offset, data->oi) < 0) {
+		if (packed_object_info_with_index_pos(pack, offset,
+						      &index_pos, data->oi) < 0) {
 			mark_bad_packed_object(pack, oid);
 			return -1;
 		}