diff --git a/src/geef_odb.erl b/src/geef_odb.erl
index 4d80c64..fa6d8dd 100644
--- a/src/geef_odb.erl
+++ b/src/geef_odb.erl
@@ -3,5 +3,6 @@
 
 -include("geef_records.hlr").
 
+-spec exists(odb(), string()) -> boolean().
 exists(#odb{handle=Handle}, Sha) ->
     geef:odb_object_exists(Handle, Sha).
diff --git a/src/geef_records.hlr b/src/geef_records.hlr
index f462633..2d033f4 100644
--- a/src/geef_records.hlr
+++ b/src/geef_records.hlr
@@ -2,4 +2,6 @@
 -record(repo, {handle}).
 -record(odb, {handle}).
 
--type repo() :: repo.
+-type ref() :: #ref{}.
+-type repo() :: #repo{}.
+-type odb() :: #odb{}.
diff --git a/src/geef_ref.erl b/src/geef_ref.erl
index 14d85a5..bf67a45 100644
--- a/src/geef_ref.erl
+++ b/src/geef_ref.erl
@@ -4,11 +4,12 @@
 
 -include("geef_records.hlr").
 
+-spec new(term()) -> ref().
 new(Handle) ->
     Type = geef:reference_type(Handle),
     #ref{handle=Handle, type=Type}.
 
--spec lookup(term(), iolist()) -> term().
+-spec lookup(repo(), iolist()) -> {ok, ref()} | {error, term()}.
 lookup(#repo{handle=Handle}, Refname) ->
     case geef:reference_lookup(Handle, Refname) of
 	{ok, Ref} ->
@@ -17,6 +18,7 @@ lookup(#repo{handle=Handle}, Refname) ->
 	    Other
     end.
 
+-spec resolve(ref()) -> {ok, ref()} | {error, term()}.
 resolve(#ref{handle=Handle}) ->
     case geef:reference_resolve(Handle) of
 	{ok, Ref} ->
@@ -25,6 +27,6 @@ resolve(#ref{handle=Handle}) ->
 	    Other
     end.
 
--spec target(term()) -> binary().
+-spec target(ref()) -> binary().
 target(#ref{handle=Handle, type=oid}) ->
     geef:reference_target(Handle).
diff --git a/src/geef_repo.erl b/src/geef_repo.erl
index 2315b1d..9dda368 100644
--- a/src/geef_repo.erl
+++ b/src/geef_repo.erl
@@ -4,19 +4,23 @@
 
 -include("geef_records.hlr").
 
+-spec path(repo()) -> binary().
 path(#repo{handle=Handle}) ->
     geef:repository_get_path(Handle).
 
+-spec workdir(repo()) -> binary().
 workdir(#repo{handle=Handle}) ->
     geef:repository_get_workdir(Handle).
 
+-spec is_bare(repo()) -> boolean().
 is_bare(#repo{handle=Handle}) ->
     geef:repository_is_bare(Handle).
 
+-spec references(repo()) -> [binary()].
 references(#repo{handle=Handle}) ->
     geef:reference_list(Handle).
 
--spec open(iolist()) -> {ok, term()} | {error, term()}.
+-spec open(iolist()) -> {ok, repo()} | {error, term()}.
 open(Path) ->
     case geef:repository_open(Path) of
 	{ok, Handle} ->