diff --git a/scripts/install-essentials b/scripts/install-essentials
index e25b84e..9c18985 100755
--- a/scripts/install-essentials
+++ b/scripts/install-essentials
@@ -6,35 +6,10 @@ IFS=$'\n\t'
 # We install `git-core` as some tooling expect `/usr/bin/git`
 # other tools that rely on PATH ordering will pick a one in `/usr/local`
 # if present
-function install_debian_stretch_deps() {
-    apt-get install -y \
-            curl wget build-essential apt-utils locales openssh-client \
-            libssl-dev libyaml-dev libreadline6-dev zlib1g-dev \
-            libncurses5-dev libffi-dev libgdbm3 libgdbm-dev \
-            ca-certificates checkinstall libxml2-dev \
-            libxslt-dev libcurl4-openssl-dev libicu-dev \
-            logrotate python-docutils pkg-config cmake nodejs \
-            libkrb5-dev postgresql-client mysql-client unzip \
-            libsqlite3-dev libpq-dev libpng-dev libjpeg-dev libzstd-dev \
-            libre2-dev libevent-dev gettext rsync git-core lsb-release
-}
-
-function install_debian_buster_deps() {
-    apt-get install -y \
-            curl wget build-essential apt-utils locales openssh-client \
-            libssl-dev libyaml-dev libreadline-dev zlib1g-dev \
-            libncurses5-dev libffi-dev ca-certificates libxml2-dev \
-            libxslt1-dev libcurl4-openssl-dev libicu-dev \
-            logrotate python-docutils pkg-config cmake \
-            libkrb5-dev postgresql-client unzip \
-            libsqlite3-dev libpq-dev libpng-dev libjpeg-dev libzstd-dev \
-            libre2-dev libevent-dev gettext rsync git-core lsb-release
-}
-
 function install_debian_bullseye_deps() {
     apt-get install -y \
-            curl wget build-essential apt-utils locales openssh-client \
-            libssl-dev libyaml-dev libreadline-dev zlib1g-dev \
+            curl wget build-essential apt-utils clang locales openssh-client \
+            libclang-dev libssl-dev libyaml-dev libreadline-dev llvm-dev zlib1g-dev \
             libncurses5-dev libffi-dev ca-certificates libxml2-dev \
             libxslt1-dev libcurl4-openssl-dev libicu-dev \
             logrotate python3-docutils pkg-config cmake \
@@ -51,12 +26,6 @@ function prepare_debian_environment() {
     VERSION=`cat /etc/issue | cut -d ' ' -f 3`
 
     case "$VERSION" in
-        9)
-            install_debian_stretch_deps
-        ;;
-        10)
-            install_debian_buster_deps
-        ;;
         11)
             install_debian_bullseye_deps
         ;;
@@ -81,7 +50,7 @@ function prepare_ubi_environment() {
     yum update -y
 
     yum install -by --nodocs \
-                autoconf cmake gcc gcc-c++ make patch perl bzip2 \
+                autoconf clang-devel cmake gcc gcc-c++ make patch perl bzip2 \
                 libedit ncurses uuid libarchive curl-devel \
                 libicu-devel libffi-devel libuuid-devel openssl-devel \
                 ncurses-devel pcre2-devel zlib-devel libstdc++-static \
diff --git a/scripts/lib/custom-docker-build b/scripts/lib/custom-docker-build
index 4a0e08b..48c69e9 100755
--- a/scripts/lib/custom-docker-build
+++ b/scripts/lib/custom-docker-build
@@ -325,12 +325,12 @@ function parse_arguments() {
     # 1. `CUSTOM_DOCKER_IMAGE` - Defines the reference of image used as
     #                            base for building images. Follows a
     #                            valid docker image reference format
-    #                              - "debian:buster"
+    #                              - "debian:bullseye"
     #                              - "registry.access.redhat.com/ubi8/ubi:8.6"
     # 2. `BUILD_OS`            - Used by installation scripts of various
     #                            components to detect the OS being worked
     #                            on. Follows regular docker image:tag
-    #                            format - "debian:buster" or "ubi:8.6".
+    #                            format - "debian:bullseye" or "ubi:8.6".
 
     TARGETARCH=${ARCH:-amd64}