diff --git a/.github/workflows/build-and-test.yml b/.github/workflows/build-and-test.yml
index 34f006a..fe33bb5 100644
--- a/.github/workflows/build-and-test.yml
+++ b/.github/workflows/build-and-test.yml
@@ -14,8 +14,8 @@ jobs:
     strategy:
       matrix:
         go:
+          - '1.21'
           - '1.20'
-          - '1.19'
 
     steps:
       - uses: actions/checkout@v3
@@ -52,7 +52,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@v3
         with:
-          go-version: '1.20'
+          go-version: '1.21'
 
       - name: Build
         run: go build ./...
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 545ea81..dfe2c1c 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -20,7 +20,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@v3
         with:
-          go-version: '1.20'
+          go-version: '1.21'
           check-latest: true
 
       - name: Setup Node.js
diff --git a/Dockerfile b/Dockerfile
index a243b9d..1517ff7 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -12,7 +12,7 @@ RUN yarn install --frozen-lockfile --non-interactive
 RUN yarn run build
 
 ### Build backend
-FROM golang:1.20-alpine3.18 as backend
+FROM golang:1.21-alpine3.19 as backend
 RUN apk add --no-cache --virtual .build-deps g++ git make
 WORKDIR /build
 COPY . .
@@ -23,7 +23,7 @@ RUN go build -o inbucket \
   -v ./cmd/inbucket
 
 ### Run in minimal image
-FROM alpine:3.18
+FROM alpine:3.19
 RUN apk --no-cache add tzdata
 WORKDIR /opt/inbucket
 RUN mkdir bin defaults ui
diff --git a/shell.nix b/shell.nix
index a6ea10f..9f11452 100644
--- a/shell.nix
+++ b/shell.nix
@@ -22,7 +22,7 @@ pkgs.mkShell {
     elmPackages.elm-json
     elmPackages.elm-language-server
     elmPackages.elm-test
-    go_1_20
+    go_1_21
     golint
     gopls
     nodejs_18