diff --git a/docs/duck/realmfs.duck b/docs/duck/realmfs.duck
index b87edc8..e083591 100644
--- a/docs/duck/realmfs.duck
+++ b/docs/duck/realmfs.duck
@@ -53,7 +53,7 @@ The apt source lines use the special Apt-Cacher NG syntax.
 [code]
   /etc/apt/sources.list
 
-  deb http://HTTPS///deb.debian.org/debian buster main contrib non-free
+  deb http://HTTPS///deb.debian.org/debian bullseye main contrib non-free
 
 Using a package cache avoids downloading and storing packages multiple times
 when updating multiple RealmFS images. It also makes it possible to download and
diff --git a/realmfs-builder/basic-image.conf b/realmfs-builder/basic-image.conf
index d14ec8c..7c355dd 100644
--- a/realmfs-builder/basic-image.conf
+++ b/realmfs-builder/basic-image.conf
@@ -1 +1 @@
-PACKAGES="man manpages vim-nox iputils-ping tmux vifm gnome-terminal firefox nautilus eog evince unzip x264 yelp"
+PACKAGES="man manpages neovim iputils-ping tmux vifm gnome-terminal firefox nautilus eog evince unzip x264 yelp"
diff --git a/realmfs-builder/build-template.conf b/realmfs-builder/build-template.conf
index b2f6950..fea3dbb 100644
--- a/realmfs-builder/build-template.conf
+++ b/realmfs-builder/build-template.conf
@@ -26,7 +26,7 @@ PACKAGES="man manpages vim-nox iputils-ping tmux gnome-terminal firefox nautilus
 # they can just be deleted.  Or you can keep them, the result will be the same.
 #
 
-DEBIAN_RELEASE="buster"
+DEBIAN_RELEASE="bullseye"
 DEBIAN_MIRROR="https://deb.debian.org/debian"
 
 #
diff --git a/realmfs-builder/common.inc b/realmfs-builder/common.inc
index 765ee43..ba84a99 100644
--- a/realmfs-builder/common.inc
+++ b/realmfs-builder/common.inc
@@ -1,6 +1,6 @@
 
 : ${DEBIAN_MIRROR:="https://deb.debian.org/debian"}
-: ${DEBIAN_RELEASE:="buster"}
+: ${DEBIAN_RELEASE:="bullseye"}
 
 BASE_PACKAGES="iproute2 less xz-utils sudo dbus libpam-systemd openssh-client packagekit-gtk3-module libcanberra-gtk3-module libpulse0 fonts-roboto-hinted bash-completion"
 
diff --git a/realmfs-builder/realmfs-modules/write-apt-sources b/realmfs-builder/realmfs-modules/write-apt-sources
index 0457073..f48c803 100644
--- a/realmfs-builder/realmfs-modules/write-apt-sources
+++ b/realmfs-builder/realmfs-modules/write-apt-sources
@@ -2,7 +2,7 @@ info "Writing /etc/apt/sources.list"
 
 {
     echo "deb ${DEBIAN_MIRROR} ${DEBIAN_RELEASE} main contrib non-free"
-    echo "deb ${DEBIAN_MIRROR}-security ${DEBIAN_RELEASE}/updates main contrib non-free"
+    echo "deb ${DEBIAN_MIRROR}-security ${DEBIAN_RELEASE}-security main contrib non-free"
     echo "deb ${DEBIAN_MIRROR} unstable main"
 
 } > /etc/apt/sources.list