diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 00000000..b2f35201
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,106 @@
+name: CI
+
+on:
+  push:
+    branches: "*"
+  pull_request:
+    branches: "*"
+
+permissions: {}
+
+jobs:
+  # On Ubuntu, because that is the standard OS of GitHub Actions.
+  build_ubuntu:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Install build dependencies
+      run: sudo apt-get update && sudo apt-get install -y libusb-1.0-0-dev libsystemd-dev libev-dev libfmt-dev libinih-dev
+
+    - uses: actions/checkout@v4
+      with:
+        fetch-depth: 0 # Full history to be able to determine version number
+
+    - name: Bootstrap
+      run: sh bootstrap.sh
+
+    - name: Configure
+      run: ./configure
+
+    - name: Build
+      run: make -j$(nproc)
+
+    - name: Install
+      run: sudo make -j1 install
+
+  # On Alpine, because it's a tiny distro heavily used in containers.
+  build_alpine:
+
+    runs-on: ubuntu-latest
+    container: alpine
+
+    steps:
+    - name: Install build dependencies
+      run: apk update && apk add git build-base autoconf automake libtool argp-standalone linux-headers libusb-dev libev-dev fmt-dev inih-dev
+
+    - name: Configure git in container
+      run: |
+        git config --global --add safe.directory "$GITHUB_WORKSPACE"
+
+    - uses: actions/checkout@v4
+      with:
+        fetch-depth: 0 # Full history to be able to determine version number
+
+    - name: Bootstrap
+      run: sh bootstrap.sh
+
+    - name: Configure
+      run: ./configure --disable-systemd
+
+    - name: Build
+      run: make -j$(nproc)
+
+    - name: Install
+      run: make -j1 install
+
+  # Debian packaging; May break when code changes require updates to the Debian package.
+  # Merges the pushed/proposed code changes to the `debian` branch and builds that then.
+  package_debian:
+
+    strategy:
+      fail-fast: false
+      matrix:
+        release: [testing, stable, oldstable]
+    runs-on: ubuntu-latest
+    container: debian:${{ matrix.release }}-slim
+
+    # When systemd is installed, these values are set in /usr/share/pkgconfig/systemd.pc.
+    # It does not make sense to install the full systemd in a build container, though, so
+    # inject the relevant values for successful "make install" with environment variables.
+    env:
+      SYSTEMD_DIR: /lib/systemd/system
+      SYSTEMD_SYSUSERS_DIR: /usr/lib/sysusers.d
+
+    steps:
+    - name: Install dependencies
+      run: |
+        apt-get update
+        apt-get upgrade -y
+        apt-get install -y --no-install-recommends ca-certificates git sudo
+
+    - name: Configure git in container
+      run: |
+        git config --global --add safe.directory "$GITHUB_WORKSPACE"
+        git config --global user.name "Your Name"
+        git config --global user.email "you@example.com"
+
+    - uses: actions/checkout@v4
+      with:
+        fetch-depth: 0 # Full history to be able to determine version number
+
+    - name: Merge into debian branch
+      run: git checkout debian && git merge "$GITHUB_REF"
+
+    - name: Build and install
+      run: sh install-debian.sh
diff --git a/configure.ac b/configure.ac
index d06f7ba8..e0469c01 100644
--- a/configure.ac
+++ b/configure.ac
@@ -23,10 +23,10 @@ dnl ##    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 dnl ##    SUCH DAMAGE.
 
 
-AC_PREREQ([2.72])
+AC_PREREQ([2.69])
 LT_PREREQ([2.2.0])
 
-AC_INIT([knxd],m4_esyscmd(sh -c "./tools/version.sh | tr -d '\n'"))
+AC_INIT([knxd],m4_esyscmd_s([./tools/version.sh]))
 AC_CONFIG_SRCDIR([src/server/knxd.cpp])
 AM_INIT_AUTOMAKE
 LT_INIT
diff --git a/src/usb/usb.cpp b/src/usb/usb.cpp
index 5a1fbe9d..feaef78a 100644
--- a/src/usb/usb.cpp
+++ b/src/usb/usb.cpp
@@ -19,7 +19,7 @@
 
 #include <cstdlib>
 #include <cerrno>
-#include <sys/poll.h>
+#include <poll.h>
 #include "usb.h"
 #include "types.h"