diff --git a/go.mod b/go.mod
index 31cde3d..97df89c 100644
--- a/go.mod
+++ b/go.mod
@@ -2,4 +2,4 @@ module git.yetaga.in/alazyreader/libyear
 
 go 1.25.1
 
-require golang.org/x/mod v0.37.0
+require golang.org/x/mod v0.38.0
diff --git a/go.sum b/go.sum
index bfccce6..18a4bb6 100644
--- a/go.sum
+++ b/go.sum
@@ -18,3 +18,5 @@ golang.org/x/mod v0.36.0 h1:JJjpVx6myfUsUdAzZuOSTTmRE0PfZeNWzzvKrP7amb4=
 golang.org/x/mod v0.36.0/go.mod h1:moc6ELqsWcOw5Ef3xVprK5ul/MvtVvkIXLziUOICjUQ=
 golang.org/x/mod v0.37.0 h1:vF1DjpVEshcIqoEaauuHebaLk1O1forxjxBaVn884JQ=
 golang.org/x/mod v0.37.0/go.mod h1:m8S8VeM9r4dzDwjrKO0a1sZP3YjeMamRRlD+fmR2Q/0=
+golang.org/x/mod v0.38.0 h1:MECBjubtXD7yj4HrhIUcywNaGeNVUdfVnxmPajOk4yk=
+golang.org/x/mod v0.38.0/go.mod h1:V6Xz0pq8TQ3dGqVQ1FVHuelZpAL0uNhSkk9ogYP3c40=