diff --git a/day6.m b/day6.m
index d3d71ae..ee8f8b5 100644
--- a/day6.m
+++ b/day6.m
@@ -7,10 +7,8 @@
 
 :- implementation.
 :- import_module int.
-:- import_module char.
 :- import_module string.
 :- import_module list.
-:- import_module maybe.
 
 :- pred all_diff(list(T)::in) is semidet.
 all_diff([]).