diff --git a/Dockerfile b/Dockerfile
index 8158be0..a6daba2 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,9 +1,10 @@
-FROM docker.io/golang:bullseye@sha256:8d717e8a7fa8035f5cfdcdc86811ffd53b7bb17542f419f2a121c4c7533d29ee as builder
+FROM docker.io/golang:1.23 as builder
 COPY . /app
 WORKDIR /app
+RUN go test ./...
 RUN GOOS=linux GOARCH=amd64 go build -o dist/
 
-FROM gcr.io/distroless/static-debian11@sha256:8ad6f3ec70dad966479b9fb48da991138c72ba969859098ec689d1450c2e6c97
+FROM gcr.io/distroless/static-debian12:latest
 COPY --from=builder /app/dist/mkcert /bin/mkcert
 USER 1001
 CMD ["/bin/mkcert"]
diff --git a/body/parser.go b/body/parser.go
index 3bb7ea6..7fc810d 100644
--- a/body/parser.go
+++ b/body/parser.go
@@ -17,13 +17,13 @@ package body
 import (
 	"encoding/json"
 	"errors"
-	"github.com/Lukasa/mkcert/certs"
 	"io"
-	"io/ioutil"
 	"log"
 	"mime"
 	"mime/multipart"
 	"strings"
+
+	"github.com/Lukasa/mkcert/certs"
 )
 
 var (
@@ -98,7 +98,7 @@ func ParseMultipartBody(f io.Reader, boundary string) ([]string, []*certs.Certif
 				label = labelVals[0]
 			}
 
-			body, err := ioutil.ReadAll(p)
+			body, err := io.ReadAll(p)
 			if err != nil {
 				log.Printf("Unexpected IO error: %v.\n", err)
 				return nil, nil, err
diff --git a/go.mod b/go.mod
index 7481e82..a4bcfd5 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,3 @@
 module github.com/Lukasa/mkcert
 
-go 1.17
+go 1.23
diff --git a/main.go b/main.go
index bb6908c..708d3cf 100644
--- a/main.go
+++ b/main.go
@@ -17,14 +17,14 @@ package main
 import (
 	"encoding/json"
 	"fmt"
-	"github.com/Lukasa/mkcert/certs"
 	"io"
 	"log"
 	"net/http"
-	"runtime"
 	"strings"
 	"sync"
 	"time"
+
+	"github.com/Lukasa/mkcert/certs"
 )
 
 const CERT_URL = "https://hg.mozilla.org/mozilla-central/raw-file/tip/security/nss/lib/ckfw/builtins/certdata.txt"
@@ -237,9 +237,6 @@ func listAllCerts(w http.ResponseWriter, r *http.Request) {
 }
 
 func main() {
-	// Before we do anything, TURN ON THE CPUS.
-	runtime.GOMAXPROCS(runtime.NumCPU())
-
 	// Start the certificate update loop.
 	go certUpdateLoop()