diff --git a/.github/workflows/citest.yml b/.github/workflows/citest.yml
index c431407..67f66ae 100644
--- a/.github/workflows/citest.yml
+++ b/.github/workflows/citest.yml
@@ -10,7 +10,7 @@ jobs:
       fail-fast: false
       matrix:
         go-version:
-          - 1.19.x
+          - 1.21.x
         os: [ubuntu-latest]
     runs-on: ${{ matrix.os }}
     steps:
diff --git a/Changes b/Changes
index 532fef2..221762a 100644
--- a/Changes
+++ b/Changes
@@ -3,6 +3,7 @@ This file documents the revision history for the Livestatus Multitool Daemon (LM
 next:
           - submit pending commands as soon as syncing started
           - accept python3 outputformat (#128)
+          - go build dependency changed to v1.21
 
 2.1.7    Fri Oct 20 10:08:38 CEST 2023
           - improve full scan sync, less delta scan timestamp filter too complex messages
diff --git a/Makefile b/Makefile
index e4b9092..fa4815e 100644
--- a/Makefile
+++ b/Makefile
@@ -8,8 +8,8 @@ GOVERSION:=$(shell \
     awk -F'go| ' '{ split($$5, a, /\./); printf ("%04d%04d", a[1], a[2]); exit; }' \
 )
 # also update README.md when changing minumum version
-MINGOVERSION:=00010019
-MINGOVERSIONSTR:=1.19
+MINGOVERSION:=00010021
+MINGOVERSIONSTR:=1.21
 BUILD:=$(shell git rev-parse --short HEAD)
 # see https://github.com/go-modules-by-example/index/blob/master/010_tools/README.md
 # and https://github.com/golang/go/wiki/Modules#how-can-i-track-tool-dependencies-for-a-module
diff --git a/README.md b/README.md
index c77fdcf..491cb76 100644
--- a/README.md
+++ b/README.md
@@ -31,7 +31,7 @@ Requirements
 
 You will need
 
- - Go >= 1.19
+ - Go >= 1.21
 
 to compile lmd.
 
diff --git a/go.mod b/go.mod
index 862fa98..bdbc30e 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/sni/lmd/v2
 
-go 1.19
+go 1.21
 
 require (
 	github.com/BurntSushi/toml v1.3.2