diff --git a/Documentation/config.txt b/Documentation/config.txt
index edf50cd211..0df004ea26 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -661,6 +661,15 @@ pack.threads::
 	machines. The required amount of memory for the delta search window
 	is however multiplied by the number of threads.
 
+pack.indexVersion::
+	Specify the default pack index version.  Valid values are 1 for
+	legacy pack index used by Git versions prior to 1.5.2, and 2 for
+	the new pack index with capabilities for packs larger than 4 GB
+	as well as proper protection against the repacking of corrupted
+	packs.  Version 2 is selected and this config option ignored
+	whenever the corresponding pack is larger than 2 GB.  Otherwise
+	the default is 1.
+
 pull.octopus::
 	The default merge strategy to use when pulling multiple branches
 	at once.
diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c
index 25ec65d0f0..545ece5da7 100644
--- a/builtin-pack-objects.c
+++ b/builtin-pack-objects.c
@@ -57,7 +57,7 @@ struct object_entry {
  * nice "minimum seek" order.
  */
 static struct object_entry *objects;
-static struct object_entry **written_list;
+static struct pack_idx_entry **written_list;
 static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
 
 static int non_empty;
@@ -577,7 +577,7 @@ static off_t write_one(struct sha1file *f,
 		e->idx.offset = 0;
 		return 0;
 	}
-	written_list[nr_written++] = e;
+	written_list[nr_written++] = &e->idx;
 
 	/* make sure off_t is sufficiently large not to wrap */
 	if (offset > offset + size)
@@ -599,7 +599,7 @@ static void write_pack_file(void)
 
 	if (do_progress)
 		progress_state = start_progress("Writing objects", nr_result);
-	written_list = xmalloc(nr_objects * sizeof(struct object_entry *));
+	written_list = xmalloc(nr_objects * sizeof(*written_list));
 
 	do {
 		unsigned char sha1[20];
@@ -651,9 +651,8 @@ static void write_pack_file(void)
 			umask(mode);
 			mode = 0444 & ~mode;
 
-			idx_tmp_name = write_idx_file(NULL,
-					(struct pack_idx_entry **) written_list,
-					nr_written, sha1);
+			idx_tmp_name = write_idx_file(NULL, written_list,
+						      nr_written, sha1);
 			snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 				 base_name, sha1_to_hex(sha1));
 			if (adjust_perm(pack_tmp_name, mode))
@@ -677,7 +676,7 @@ static void write_pack_file(void)
 
 		/* mark written objects as written to previous pack */
 		for (j = 0; j < nr_written; j++) {
-			written_list[j]->idx.offset = (off_t)-1;
+			written_list[j]->offset = (off_t)-1;
 		}
 		nr_remaining -= nr_written;
 	} while (nr_remaining && i < nr_objects);
@@ -1768,6 +1767,12 @@ static int git_pack_config(const char *k, const char *v)
 #endif
 		return 0;
 	}
+	if (!strcmp(k, "pack.indexversion")) {
+		pack_idx_default_version = git_config_int(k, v);
+		if (pack_idx_default_version > 2)
+			die("bad pack.indexversion=%d", pack_idx_default_version);
+		return 0;
+	}
 	return git_default_config(k, v);
 }
 
diff --git a/index-pack.c b/index-pack.c
index 61ea7621be..715a5bb7a6 100644
--- a/index-pack.c
+++ b/index-pack.c
@@ -683,6 +683,17 @@ static void final(const char *final_pack_name, const char *curr_pack_name,
 	}
 }
 
+static int git_index_pack_config(const char *k, const char *v)
+{
+	if (!strcmp(k, "pack.indexversion")) {
+		pack_idx_default_version = git_config_int(k, v);
+		if (pack_idx_default_version > 2)
+			die("bad pack.indexversion=%d", pack_idx_default_version);
+		return 0;
+	}
+	return git_default_config(k, v);
+}
+
 int main(int argc, char **argv)
 {
 	int i, fix_thin_pack = 0;
@@ -693,6 +704,8 @@ int main(int argc, char **argv)
 	struct pack_idx_entry **idx_objects;
 	unsigned char sha1[20];
 
+	git_config(git_index_pack_config);
+
 	for (i = 1; i < argc; i++) {
 		char *arg = argv[i];