diff --git a/c_src/index.c b/c_src/index.c
index ce270b7..fd97753 100644
--- a/c_src/index.c
+++ b/c_src/index.c
@@ -98,6 +98,7 @@ geef_index_add(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[])
 	geef_index *index;
 	const ERL_NIF_TERM *eentry;
 	int arity;
+	unsigned int tmp;
 	ErlNifBinary path, id;
 	git_index_entry entry;
 
@@ -109,12 +110,48 @@ geef_index_add(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[])
 
 	memset(&entry, 0, sizeof(entry));
 
+	if (enif_compare(eentry[1], atoms.undefined) &&
+	    !enif_get_int64(env, eentry[1], &entry.ctime.seconds))
+		return enif_make_badarg(env);
+
+	if (enif_compare(eentry[2], atoms.undefined) &&
+	    !enif_get_int64(env, eentry[2], &entry.mtime.seconds))
+		return enif_make_badarg(env);
+
+	if (enif_compare(eentry[3], atoms.undefined) &&
+	    !enif_get_uint(env, eentry[3], &entry.dev))
+		return enif_make_badarg(env);
+
+	if (enif_compare(eentry[4], atoms.undefined) &&
+	    !enif_get_uint(env, eentry[4], &entry.ino))
+		return enif_make_badarg(env);
+
 	if (!enif_get_uint(env, eentry[5], &entry.mode))
 		return enif_make_badarg(env);
 
+	if (enif_compare(eentry[6], atoms.undefined) &&
+	    !enif_get_uint(env, eentry[6], &entry.uid))
+		return enif_make_badarg(env);
+
+	if (enif_compare(eentry[7], atoms.undefined) &&
+	    !enif_get_uint(env, eentry[7], &entry.gid))
+		return enif_make_badarg(env);
+
 	if (!enif_get_int64(env, eentry[8], &entry.file_size))
 		return enif_make_badarg(env);
 
+	/* [9] comes later */
+
+	if (enif_compare(eentry[10], atoms.undefined) &&
+	    !enif_get_uint(env, eentry[10], &tmp))
+		return enif_make_badarg(env);
+	entry.flags = tmp;
+
+	if (enif_compare(eentry[11], atoms.undefined) &&
+	    !enif_get_uint(env, eentry[11], &tmp))
+		return enif_make_badarg(env);
+	entry.flags_extended = tmp;
+
 	if (!enif_inspect_iolist_as_binary(env, eentry[12], &path))
 		return enif_make_badarg(env);
 
diff --git a/test/repo_test.erl b/test/repo_test.erl
index f2c0221..5b4e3ed 100644
--- a/test/repo_test.erl
+++ b/test/repo_test.erl
@@ -36,7 +36,9 @@ index_add_test(Repo) ->
     {ok, Odb} = geef_repo:odb(Repo),
     {ok, BlobId} = geef_odb:write(Odb, Data, blob),
     {ok, Idx} = geef_index:new(),
-    Entry = #geef_index_entry{mode=8#100644, id=BlobId, path="README", size=size(Data)},
+    {NowMega, NowSecs, _} = os:timestamp(),
+    Time = NowMega * 1000000 + NowSecs,
+    Entry = #geef_index_entry{mode=8#100644, id=BlobId, path="README", size=size(Data), mtime=Time},
     ok = geef_index:add(Idx, Entry),
     {ok, TreeId} = geef_index:write_tree(Idx, Repo),
     Expected = geef_oid:parse("5a20bbbf65ea75ad4d9f995d179156824ccca3a1"),
@@ -44,6 +46,7 @@ index_add_test(Repo) ->
     [?_assertEqual(Expected, TreeId),
      ?_assertEqual(BlobId, Entry1#geef_index_entry.id),
      ?_assertEqual(size(Data), Entry1#geef_index_entry.size),
+     ?_assertEqual(Time, Entry1#geef_index_entry.mtime),
      ?_assertEqual(geef_index:count(Idx), 1)].
 
 ref_test(Repo) ->