diff --git a/erlang/apps/lib/src/pdp10_stdio.erl b/erlang/apps/lib/src/pdp10_stdio.erl
index 0ec8d0b..b9f68c4 100644
--- a/erlang/apps/lib/src/pdp10_stdio.erl
+++ b/erlang/apps/lib/src/pdp10_stdio.erl
@@ -132,8 +132,7 @@ fputc(Nonet, #file{pid = Pid}) ->
 fwrite(Nonets, #file{pid = Pid}) ->
   gen_server:call(Pid, {fwrite, Nonets}, infinity).
 
--spec fseek(#file{}, file:location())
-        -> {ok, non_neg_integer()} | {error, any()}.
+-spec fseek(#file{}, file:location()) -> ok | {error, any()}.
 fseek(#file{pid = Pid}, Location) ->
   gen_server:call(Pid, {fseek, Location}, infinity).