diff --git a/.forgejo/bin/build.sh b/.forgejo/bin/build.sh
index d9e327f..ad5e30c 100755
--- a/.forgejo/bin/build.sh
+++ b/.forgejo/bin/build.sh
@@ -7,7 +7,7 @@
 set -eu -o pipefail
 
 readonly APORTSDIR=$CI_PROJECT_DIR
-readonly REPOS="backports user"
+readonly REPOS="backports user pmos"
 readonly ALPINE_REPOS="main community testing"
 readonly ARCH=$(apk --print-arch)
 # gitlab variables
@@ -16,6 +16,8 @@ readonly BASEBRANCH=$CI_MERGE_REQUEST_TARGET_BRANCH_NAME
 : "${REPODEST:=$HOME/packages}"
 : "${MIRROR:=https://ayakael.net/api/packages/forge/alpine}"
 : "${ALPINE_MIRROR:=http://dl-cdn.alpinelinux.org/alpine}"
+: "${PMOS_MIRROR:=http://mirror.postmarketos.org/postmarketos}"
+: "${PMOS_KEY:=https://git.syndicate-lang.org/synit/pmbootstrap/raw/commit/8efee86388408c0d8de45c64fe383580ffd91700/pmb/data/keys/build.postmarketos.org.rsa.pub}"
 : "${MAX_ARTIFACT_SIZE:=300000000}" #300M
 : "${CI_DEBUG_BUILD:=}"
 
@@ -137,6 +139,22 @@ setup_system() {
 	git config --global init.defaultBranch master
 }
 
+setup_pmos() {
+	local release
+
+	case $BASEBRANCH in
+		v3.21) release="v24.12";;
+		v3.20) release="v24.6";;
+		v3.19) release="v23.12";;
+		edge) release=master;;
+		*) die "Branch \"$BASEBRANCH\" not supported!"
+	esac
+
+	doas wget "$PMOS_KEY" -P /etc/apk/keys
+	doas sh -c "echo $PMOS_MIRROR/$release >> /etc/apk/repositories"
+	doas apk update || true
+}
+
 sysinfo() {
 	printf ">>> Host system information (arch: %s, release: %s) <<<\n" "$ARCH" "$(get_release)"
 	printf "- Number of Cores: %s\n" "$(nproc)"
@@ -144,6 +162,7 @@ sysinfo() {
 	printf "- Free space: %s\n" "$(df -hP / | awk '/\/$/ {print $4}')"
 }
 
+
 copy_artifacts() {
 	cd "$APORTSDIR"
 
@@ -204,6 +223,7 @@ build_limit=$CI_ALPINE_BUILD_LIMIT
 
 for repo in $(changed_repos); do
 	set_repositories_for "$repo"
+	[ "$repo" == "pmos" ] && setup_pmos
 	built_aports=0
 	changed_aports_in_repo=$(changed_aports "$repo")
 	changed_aports_in_repo_count=$(echo "$changed_aports_in_repo" | wc -l)