diff --git a/.github/workflows/go.yml b/.github/workflows/go.yml
index eb6c5e2a..ce4a4730 100644
--- a/.github/workflows/go.yml
+++ b/.github/workflows/go.yml
@@ -16,7 +16,7 @@ jobs:
     - name: Set up Go 1.x
       uses: actions/setup-go@v2
       with:
-        go-version: ^1.20
+        go-version: ^1.21
 
     - name: Check out code into the Go module directory
       uses: actions/checkout@v2
@@ -27,5 +27,5 @@ jobs:
     - run: make test
 
     - run: make test_bench
-      
+
     - run: make test_race
diff --git a/Dockerfile b/Dockerfile
index 1e5ad848..2a923e0f 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,7 +3,7 @@
 
 # Use the offical Golang image to create a build artifact.
 # https://hub.docker.com/_/golang
-FROM golang:1.20 as builder
+FROM golang:1.21 as builder
 
 # Copy local code to the container image.
 WORKDIR /app
diff --git a/go.mod b/go.mod
index 524df9c8..4ea1a767 100644
--- a/go.mod
+++ b/go.mod
@@ -1,8 +1,8 @@
 module github.com/mat/besticon
 
-// +heroku goVersion go1.20
+// +heroku goVersion go1.21
 
-go 1.20
+go 1.21
 
 require (
 	github.com/PuerkitoBio/goquery v1.6.1