diff --git a/Dockerfile b/Dockerfile
index 53bf9be2..157ced8b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM golang:1.15.5
+FROM golang:1.20.4
 
 ENV PKG github.com/yuuki/shawk
 WORKDIR /go/src/$PKG