diff --git a/src/geef_object.erl b/src/geef_object.erl
index 5421833..1a52763 100644
--- a/src/geef_object.erl
+++ b/src/geef_object.erl
@@ -1,14 +1,31 @@
 -module(geef_object).
 
+-ifdef(TEST).
+-include_lib("eunit/include/eunit.hrl").
+-endif.
+
 -include("geef_records.hrl").
 
 -export([lookup/2]).
 
--spec lookup(repo(), oid()) -> object().
+-spec lookup(repo(), oid() | iolist()) -> object().
 lookup(#repo{handle=RepoHandle}, #oid{oid=Oid}) ->
     case geef:object_lookup(RepoHandle, Oid) of
 	{ok, Type, Handle} ->
 	    {ok, #object{type=Type, handle=Handle}};
 	Other ->
 	    Other
-    end.
+    end;
+lookup(Repo = #repo{}, Id) ->
+    lookup(Repo, geef_oid:parse(Id)).
+
+-ifdef(TEST).
+
+lookup_test() ->
+    {ok, Repo} = geef_repo:open(".."),
+    {ok, #object{type=commit}} = lookup(Repo, geef_oid:parse("b5b68cce8b92ca0e7bd48430617ac10c0f2c2923")),
+    {ok, #object{type=commit}} = lookup(Repo, "b5b68cce8b92ca0e7bd48430617ac10c0f2c2923"),
+    {ok, #object{type=commit}} = lookup(Repo, ["b5b68cce8b92ca0e7", "bd48430617ac10c0f2c2923"]),
+    {ok, #object{type=commit}} = lookup(Repo, <<"b5b68cce8b92ca0e7bd48430617ac10c0f2c2923">>).
+
+-endif.