diff --git a/Dockerfile b/Dockerfile
index 225065092..9740e81a5 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,5 @@
 # build stage
-FROM --platform=$BUILDPLATFORM golang:1.21-alpine AS builder
+FROM --platform=$BUILDPLATFORM golang:1.20-alpine AS builder
 
 WORKDIR /app
 COPY . .
diff --git a/go.mod b/go.mod
index 5ac02c6dc..fcc9d3cf0 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/jeessy2/ddns-go/v6
 
-go 1.21
+go 1.20
 
 require (
 	github.com/kardianos/service v1.2.2