diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index b802b5dd..da3a2d89 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -38,7 +38,7 @@ jobs:
         name: Set up Go
         uses: actions/setup-go@v2
         with:
-          go-version: 1.13
+          go-version: 1.15
       -
         name: Cache Go modules
         uses: actions/cache@v2
@@ -124,7 +124,7 @@ jobs:
         with:
           context: .
           file: ./Dockerfile
-          platforms: linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64,linux/386,linux/ppc64le,linux/s390x
+          platforms: linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64,linux/386,linux/ppc64le
           push: ${{ github.event_name != 'pull_request' }}
           tags: ${{ steps.docker_meta.outputs.tags }}
           build-args: |
diff --git a/.github/workflows/gosum.yml b/.github/workflows/gosum.yml
index d11e40f6..d68cc27a 100644
--- a/.github/workflows/gosum.yml
+++ b/.github/workflows/gosum.yml
@@ -20,7 +20,7 @@ jobs:
         name: Set up Go
         uses: actions/setup-go@v2
         with:
-          go-version: 1.13
+          go-version: 1.15
       -
         name: Tidy
         run: |
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 379722c9..f91b743e 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -31,7 +31,7 @@ jobs:
         name: Set up Go
         uses: actions/setup-go@v2
         with:
-          go-version: 1.13
+          go-version: 1.15
       -
         name: Cache Go modules
         uses: actions/cache@v2
diff --git a/Dockerfile b/Dockerfile
index 44669383..c3afc249 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-ARG GO_VERSION=1.13
+ARG GO_VERSION=1.15
 ARG VERSION=dev
 
 FROM --platform=${BUILDPLATFORM:-linux/amd64} tonistiigi/xx:golang AS xgo
@@ -30,7 +30,6 @@ RUN apk --update --no-cache add \
   && rm -rf /tmp/* /var/cache/apk/*
 
 COPY --from=build /opt/diun /usr/local/bin/diun
-COPY --from=build /usr/local/go/lib/time/zoneinfo.zip /usr/local/go/lib/time/zoneinfo.zip
 RUN diun --version
 
 ENV DIUN_DB_PATH="/data/diun.db"
diff --git a/cmd/main.go b/cmd/main.go
index 98c749cf..5cf6bf39 100644
--- a/cmd/main.go
+++ b/cmd/main.go
@@ -7,6 +7,7 @@ import (
 	"runtime"
 	"strings"
 	"syscall"
+	_ "time/tzdata"
 
 	"github.com/alecthomas/kong"
 	"github.com/crazy-max/diun/v4/internal/app"
diff --git a/docs/install/docker.md b/docs/install/docker.md
index 23fc9d2f..f2f25aa5 100644
--- a/docs/install/docker.md
+++ b/docs/install/docker.md
@@ -24,7 +24,6 @@ Image: crazymax/diun:latest
    - linux/arm64
    - linux/386
    - linux/ppc64le
-   - linux/s390x
 ```
 
 ## Volumes
diff --git a/go.mod b/go.mod
index 87c78974..124b10e1 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/crazy-max/diun/v4
 
-go 1.13
+go 1.15
 
 require (
 	github.com/alecthomas/kong v0.2.11