diff --git a/go.mod b/go.mod
index 97df89c..85cea67 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 v0.38.0
+require golang.org/x/mod v0.39.0
diff --git a/go.sum b/go.sum
index 18a4bb6..e33ffa2 100644
--- a/go.sum
+++ b/go.sum
@@ -20,3 +20,5 @@ 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=
+golang.org/x/mod v0.39.0 h1:UF5zwQdCRRUpHfyPwr7d4UrGiVeldIsogtzWVnczL74=
+golang.org/x/mod v0.39.0/go.mod h1:bvIbwjQ0HUFFf5AKukeeYQG4ZBUG9yxQbR9aEweIwYY=