diff --git a/Makefile b/Makefile
index 95a2339..a19f119 100644
--- a/Makefile
+++ b/Makefile
@@ -40,7 +40,7 @@ checksums:
 	mv *.iso iso/
 	last_tag=$$(git tag | tail -n1); \
 	cd iso/; \
-	rename "s/live-image/dlc-$$last_tag-debian-buster/" *; \
+	rename "s/live-image/dlc-$$last_tag-debian-bullseye/" *; \
 	sha512sum *.iso  > SHA512SUMS; \
 
 # the signing key must be present and loaded on the build machine
@@ -73,18 +73,18 @@ test_imagesize:
 # rsync -avzP $BUILD_HOST:/var/debian-live-config/debian-live-config/iso/ ./
 test_kvm_bios:
 	# Run the resulting image in KVM/virt-manager (legacy BIOS mode)
-	sudo virt-install --name dlc-test --boot cdrom --video virtio --disk path=$$PWD/dlc-test-disk0.qcow2,format=qcow2,size=20,device=disk,bus=virtio,cache=none --cdrom 'iso/dlc-2.2.5-debian-buster-amd64.hybrid.iso' --memory 2048 --vcpu 2
-	sudo virsh destroy dlc-test
-	sudo virsh undefine dlc-test
-	sudo rm $$PWD/dlc-test-disk0.qcow2
+	virt-install --name dlc-test --boot cdrom --video virtio --disk path=$$PWD/dlc-test-disk0.qcow2,format=qcow2,size=20,device=disk,bus=virtio,cache=none --cdrom 'iso/dlc-2.2.5-debian-bullseye-amd64.hybrid.iso' --memory 4096 --vcpu 2
+	virsh destroy dlc-test
+	virsh undefine dlc-test
+	rm -f $$PWD/dlc-test-disk0.qcow2
 
 test_kvm_uefi:
 	# Run the resulting image in KVM/virt-manager (UEFI mode)
 	# UEFI support must be enabled in QEMU config for EFI install tests https://wiki.archlinux.org/index.php/Libvirt#UEFI_Support (/usr/share/OVMF/*.fd)
-	sudo virt-install --name dlc-test --boot loader=/usr/share/OVMF/OVMF_CODE.fd --video virtio --disk path=$$PWD/dlc-test-disk0.qcow2,format=qcow2,size=20,device=disk,bus=virtio,cache=none --cdrom 'iso/dlc-2.2.5-debian-buster-amd64.hybrid.iso' --memory 2048 --vcpu 2
-	sudo virsh destroy dlc-test
-	sudo virsh undefine dlc-test
-	sudo rm $$PWD/dlc-test-disk0.qcow2
+	virt-install --name dlc-test --boot loader=/usr/share/OVMF/OVMF_CODE.fd --video virtio --disk path=$$PWD/dlc-test-disk0.qcow2,format=qcow2,size=20,device=disk,bus=virtio,cache=none --cdrom 'iso/dlc-2.2.5-debian-bullseye-amd64.hybrid.iso' --memory 4096 --vcpu 2
+	virsh destroy dlc-test
+	virsh undefine dlc-test
+	rm -f $$PWD/dlc-test-disk0.qcow2
 
 #################################
 
diff --git a/README.md b/README.md
index 748e125..0e7cc4c 100644
--- a/README.md
+++ b/README.md
@@ -20,7 +20,7 @@ This repository contains the `live-build` configuration and scripts used to buil
 
 ## Download
 
-**[![](doc/md/download.png) Download .ISO image](https://github.com/nodiscc/debian-live-config/releases/download/2.2.5/dlc-2.2.5-debian-buster-amd64.hybrid.iso)** (64-bit)
+**[![](doc/md/download.png) Download .ISO image](https://github.com/nodiscc/debian-live-config/releases/download/2.2.5/dlc-2.2.5-debian-bullseye-amd64.hybrid.iso)** (64-bit)
 
 
 ## Documentation
diff --git a/auto/config b/auto/config
index 9d67eee..df5259f 100755
--- a/auto/config
+++ b/auto/config
@@ -16,10 +16,10 @@ lb config noauto \
 --clean \
 --debconf-frontend dialog \
 --debian-installer live \
---debian-installer-distribution buster \
+--debian-installer-distribution bullseye \
 --debian-installer-gui true \
 --debootstrap-options "--include=apt-transport-https,ca-certificates,openssl" \
---distribution buster \
+--distribution bullseye \
 --firmware-binary true \
 --firmware-chroot true \
 --initramfs live-boot \
diff --git a/config/archives/debian-buster-updates-security-backports.list.binary b/config/archives/debian-buster-updates-security-backports.list.binary
deleted file mode 100644
index 2d3dbcc..0000000
--- a/config/archives/debian-buster-updates-security-backports.list.binary
+++ /dev/null
@@ -1,5 +0,0 @@
-deb https://deb.debian.org/debian/ buster main contrib non-free
-deb http://security.debian.org/ buster/updates main contrib non-free
-deb https://deb.debian.org/debian/ buster-proposed-updates main contrib non-free
-deb https://deb.debian.org/debian/ buster-updates main contrib non-free
-deb https://deb.debian.org/debian/ buster-backports main contrib non-free
diff --git a/config/archives/debian-buster-updates-security-backports.list.chroot b/config/archives/debian-buster-updates-security-backports.list.chroot
deleted file mode 120000
index a4825d0..0000000
--- a/config/archives/debian-buster-updates-security-backports.list.chroot
+++ /dev/null
@@ -1 +0,0 @@
-../includes.chroot/etc/apt/sources.list.d/debian-buster-updates-security-backports.list
\ No newline at end of file
diff --git a/config/archives/debian-updates-security-backports.list.binary b/config/archives/debian-updates-security-backports.list.binary
new file mode 100644
index 0000000..d2ad0ae
--- /dev/null
+++ b/config/archives/debian-updates-security-backports.list.binary
@@ -0,0 +1,5 @@
+deb https://deb.debian.org/debian/ bullseye main contrib non-free
+deb http://security.debian.org/debian-security bullseye-security main contrib non-free
+deb https://deb.debian.org/debian/ bullseye-proposed-updates main contrib non-free
+deb https://deb.debian.org/debian/ bullseye-updates main contrib non-free
+deb https://deb.debian.org/debian/ bullseye-backports main contrib non-free
diff --git a/config/archives/debian-updates-security-backports.list.chroot b/config/archives/debian-updates-security-backports.list.chroot
new file mode 100644
index 0000000..d2ad0ae
--- /dev/null
+++ b/config/archives/debian-updates-security-backports.list.chroot
@@ -0,0 +1,5 @@
+deb https://deb.debian.org/debian/ bullseye main contrib non-free
+deb http://security.debian.org/debian-security bullseye-security main contrib non-free
+deb https://deb.debian.org/debian/ bullseye-proposed-updates main contrib non-free
+deb https://deb.debian.org/debian/ bullseye-updates main contrib non-free
+deb https://deb.debian.org/debian/ bullseye-backports main contrib non-free
diff --git a/config/includes.chroot/etc/apt/apt.conf.d/50unattended-upgrades b/config/includes.chroot/etc/apt/apt.conf.d/50unattended-upgrades
index 1b597ba..db5600b 100644
--- a/config/includes.chroot/etc/apt/apt.conf.d/50unattended-upgrades
+++ b/config/includes.chroot/etc/apt/apt.conf.d/50unattended-upgrades
@@ -20,7 +20,7 @@
 // Within lines unattended-upgrades allows 2 macros whose values are
 // derived from /etc/debian_version:
 //   ${distro_id}            Installed origin.
-//   ${distro_codename}      Installed codename (eg, "buster")
+//   ${distro_codename}      Installed codename (eg, "bullseye")
 Unattended-Upgrade::Origins-Pattern {
         // Codename based matching:
         // This will follow the migration of a release through different
diff --git a/doc/md/custom.md b/doc/md/custom.md
index 895407b..42b323d 100644
--- a/doc/md/custom.md
+++ b/doc/md/custom.md
@@ -5,11 +5,11 @@
 The actual ISO image build process is managed by the [live-build](https://www.debian.org/devel/debian-live/) suite of tools. For more details, read the `live-build` documentation:
 
 * [Live Systems manual](https://live-team.pages.debian.net/live-manual/html/live-manual/index.en.html)
-* [`man lb config`](httpshttps://manpages.debian.org/buster/live-build/lb_config.1.en.html)
-* [`man lb build`](https://manpages.debian.org/buster/live-build/lb_build.1.en.html)
-* [`man lb clean`](https://manpages.debian.org/buster/live-build/lb_clean.1.en.html)
-* [`man live-build`](https://manpages.debian.org/stretch/live-build/live-build.7.en.html)
-* `/usr/share/doc/live-manual/pdf/live-manual.portrait.en.a4.pdf.gz` ([live-manual](https://packages.debian.org/buster/live-manual) package)
+* [`man lb config`](httpshttps://manpages.debian.org/bullseye/live-build/lb_config.1.en.html)
+* [`man lb build`](https://manpages.debian.org/bullseye/live-build/lb_build.1.en.html)
+* [`man lb clean`](https://manpages.debian.org/bullseye/live-build/lb_clean.1.en.html)
+* [`man live-build`](https://manpages.debian.org/bullseye/live-build/live-build.7.en.html)
+* `/usr/share/doc/live-manual/pdf/live-manual.portrait.en.a4.pdf.gz` ([live-manual](https://packages.debian.org/bullseye/live-manual) package)
 
 
 ## Build using the default configuration
@@ -58,8 +58,8 @@ You need some disk space for the download and build caches. The build directory
 
 ### auto/
 
-* `auto/config` sets basic configuration settings for the build (architecture, boot configuration, installer...), see [`man lb config`](https://manpages.debian.org/buster/live-build/lb_config.1.en.html)
-* `auto/clean` is run automatically before each build to ensure the build directory is free of any artifacts from previous builds (download caches are kept). See [`man lb clean`](https://manpages.debian.org/buster/live-build/lb_clean.1.en.html)
+* `auto/config` sets basic configuration settings for the build (architecture, boot configuration, installer...), see [`man lb config`](https://manpages.debian.org/bullseye/live-build/lb_config.1.en.html)
+* `auto/clean` is run automatically before each build to ensure the build directory is free of any artifacts from previous builds (download caches are kept). See [`man lb clean`](https://manpages.debian.org/bullseye/live-build/lb_clean.1.en.html)
 * `auto/build` contains the command used for the build, and basic logging settings
 
 
@@ -67,7 +67,7 @@ You need some disk space for the download and build caches. The build directory
 
 Files to copy to the resulting live system (eg. modified configuration or data files under `etc/, opt/, usr/, ...`)
 
-Scripts and data that do not belong to an existing Debian package _should_ be distributed as [custom packages](http://wiki.debian.org/Packaging), and not stashed directly into this directory. Debian packages can also handle custom configuration files (see [`man dpkg-divert`](https://manpages.debian.org/buster/dpkg/dpkg-divert.1.en.html)).
+Scripts and data that do not belong to an existing Debian package _should_ be distributed as [custom packages](http://wiki.debian.org/Packaging), and not stashed directly into this directory. Debian packages can also handle custom configuration files (see [`man dpkg-divert`](https://manpages.debian.org/bullseye/dpkg/dpkg-divert.1.en.html)).
 
 For example, to add custom files/unpackaged programs inside your live system:
 
@@ -97,11 +97,7 @@ Caveats:
  - Packages placed here will _not_ receive upgrades through APT (unless they are someday added to official Debian repositories)
  - Packages placed here are not GPG-signed. Ensure you download/build the package over a secure channel.
 
-```bash
-# example addition of a third-party program
-mkdir -pv config/packages.chroot
-wget -N -nv --show-progress -P config/packages.chroot/ https://download.opensuse.org/repositories/home:/strycore/Debian_9.0/amd64/lutris_0.5.2.2_amd64.deb
-```
+See [Makefile.extra](https://gitlab.com/nodiscc/debian-live-config/-/blob/master/Makefile.extra) for examples.
 
 
 ### config/includes.installer/
@@ -149,7 +145,7 @@ Currently only 2 locales (english and french) are pre-generated, other languages
     - [ ] Automated whole disk partitioning
     - [ ] Manual
 - [ ] Copy latest CHANGELOG.md entry to a [new Github release](https://github.com/nodiscc/debian-live-config/releases)
-- [ ] attach `dlc-X.Y.Z-debian-buster-amd64.hybrid.iso dlc-release.key SHA512SUMS SHA512SUMS.sign` to the releases
+- [ ] attach `dlc-X.Y.Z-debian-bullseye-amd64.hybrid.iso dlc-release.key SHA512SUMS SHA512SUMS.sign` to the releases
 - `Publish release`
  
 
diff --git a/doc/md/download-and-installation.md b/doc/md/download-and-installation.md
index cbc2baa..cc365b5 100644
--- a/doc/md/download-and-installation.md
+++ b/doc/md/download-and-installation.md
@@ -3,20 +3,20 @@
 ## Hardware Requirements
 
 - Computer with x86_64 CPU
-- Memory: min 1024MB, recommended 2GB+
+- Memory: min 2GB, recommended 4GB+
 - Recommended storage: 15GB+ hard drive or SSD (operating system and programs), 10-∞GB (user data)
 - 2GB+ USB drive or DVD-R for the installation media
 
 
 ## Download
 
-**[![](download.png) Download](https://github.com/nodiscc/debian-live-config/releases/download/2.2.5/dlc-2.2.5-debian-buster-amd64.hybrid.iso)** the latest ISO image
+**[![](download.png) Download](https://github.com/nodiscc/debian-live-config/releases/download/2.2.5/dlc-2.2.5-debian-bullseye-amd64.hybrid.iso)** the latest ISO image
 
 (Recommended) verify file integrity and authenticity with GPG:
 
 ```bash
 # download the iso, signing key, checksums and signature
-wget https://github.com/nodiscc/debian-live-config/releases/download/2.2.5/dlc-2.2.5-debian-buster-amd64.hybrid.iso
+wget https://github.com/nodiscc/debian-live-config/releases/download/2.2.5/dlc-2.2.5-debian-bullseye-amd64.hybrid.iso
 wget https://github.com/nodiscc/debian-live-config/releases/download/2.2.5/dlc-release.key
 wget https://github.com/nodiscc/debian-live-config/releases/download/2.2.5/SHA512SUMS
 wget https://github.com/nodiscc/debian-live-config/releases/download/2.2.5/SHA512SUMS.sign
@@ -35,7 +35,7 @@ sha512sum -c SHA512SUMS
 #### To USB - From Linux
 
   * Insert a 2GB+ USB drive
-  * Right-click the ISO image file, and click `Open with ... > Disk image writer` (requires [gnome-disks](https://packages.debian.org/buster/gnome-disk-utility)) **Caution, all data on the USB drive will be erased**
+  * Right-click the ISO image file, and click `Open with ... > Disk image writer` (requires [gnome-disks](https://packages.debian.org/bullseye/gnome-disk-utility)) **Caution, all data on the USB drive will be erased**
   * Or, using the command line: Identify your USB drive device name (eg. `/dev/sdc`) using the `lsblk` command; Write the ISO image to the drive using `sudo dd /path/to/live-image.iso /dev/sdXXX`.
 
 ![](https://i.imgur.com/1fYOBty.png)
diff --git a/doc/md/index.md b/doc/md/index.md
index b7f814a..0e17d93 100644
--- a/doc/md/index.md
+++ b/doc/md/index.md
@@ -20,7 +20,7 @@ This repository contains the `live-build` configuration and scripts used to buil
 
 ## Download
 
-**[![](download.png) Download .ISO image](https://github.com/nodiscc/debian-live-config/releases/download/2.2.5/dlc-2.2.5-debian-buster-amd64.hybrid.iso)** (64-bit)
+**[![](download.png) Download .ISO image](https://github.com/nodiscc/debian-live-config/releases/download/2.2.5/dlc-2.2.5-debian-bullseye-amd64.hybrid.iso)** (64-bit)
 
 
 ## Documentation