diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7c743dc99..3d85d391c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -122,8 +122,7 @@ jobs:
         # so, set it here, again.
         PKG_CONFIG_PATH: "/usr/local/opt/openssl@1.1/lib/pkgconfig:$PKG_CONFIG_PATH"
       run: |
-        # pip install -e .
-        python setup.py -v develop
+        pip install -e .
     - name: run pytest via tox
       env:
         # we already have that in the global env, but something is broken and overwrites that.
diff --git a/Vagrantfile b/Vagrantfile
index c8d382e23..2a56aa8b5 100644
--- a/Vagrantfile
+++ b/Vagrantfile
@@ -193,8 +193,7 @@ def install_borg(fuse)
     pip install -U wheel  # upgrade wheel, might be too old
     cd borg
     pip install -r requirements.d/development.lock.txt
-    python setup.py clean
-    python setup.py clean2
+    python setup.py clean clean2
     pip install -e .[#{fuse}]
   EOF
 end
diff --git a/requirements.d/development.lock.txt b/requirements.d/development.lock.txt
index c2a765cd4..55a51cdea 100644
--- a/requirements.d/development.lock.txt
+++ b/requirements.d/development.lock.txt
@@ -2,6 +2,7 @@ setuptools==69.0.3
 setuptools-scm==8.0.4
 pip==23.3.2
 virtualenv==20.25.0
+build==1.0.3
 pkgconfig==1.5.5
 tox==4.11.4
 pytest==7.4.3
diff --git a/requirements.d/development.txt b/requirements.d/development.txt
index 270cdaf5a..309bd72e6 100644
--- a/requirements.d/development.txt
+++ b/requirements.d/development.txt
@@ -2,6 +2,7 @@ setuptools>=64
 setuptools_scm>=8
 pip
 virtualenv
+build
 pkgconfig
 tox
 pytest
diff --git a/scripts/sdist-sign b/scripts/sdist-sign
index 50758a30a..81dd92365 100755
--- a/scripts/sdist-sign
+++ b/scripts/sdist-sign
@@ -13,7 +13,7 @@ else
     GPG=qubes-gpg-client-wrapper
 fi
 
-python setup.py sdist
+python -m build
 
 D=dist/borgbackup-$R.tar.gz