diff --git a/action.bash b/action.bash
index de7b7db..96d91a9 100755
--- a/action.bash
+++ b/action.bash
@@ -6,12 +6,13 @@ TARGET=icinga/icingaweb2
 
 mkimg () {
 	test -n "$TAG"
+	test -n "$MODE"
 
 	node /actions/checkout/dist/index.js |grep -vFe ::add-matcher::
 
 	git archive --prefix=icingaweb2/ HEAD |tar -x
 
-	/get-mods.sh "$1"
+	/get-mods.sh "$MODE"
 	/composer.bash
 	patch -d icingaweb2 -p0 < /icingaweb2.patch
 
@@ -31,39 +32,24 @@ push () {
 	fi
 }
 
-# Matches Git references that start with `refs/` and then continue with `heads/` or `tags/`.
-# An optional `v` that follows is ignored. Then the tag or branch name is captured. These may
-# be of the following forms and what is captured of them:
-#
-#  - <form> -> g1(´heads´ or ´tags´),g2,g3
-#
-#  - v1 -> ,1,
-#  - v1.1 -> ,1.1,
-#  - v1.2-1 -> ,1.2-1,
-#  - 2.0.0 -> ,2.0.0,
-#  - master -> ,master,
-#  - main -> ,main,
-#  - something -> ,something,
-#  - verbose -> ,erbose,
-#  - vault -> ,ault,
-#  - fix/error-123 -> ,fix/error-123,error-123
-#  - fix/mistake-456 -> ,fix/mistake-456,mistake-456
-#  - fix/climate -> ,fix/climate,climate
-#  - bugfix/legacy -> ,bugfix/legacy,legacy
-#  - feature/green-energy -> ,feature/green-energy,green-energy
-#  - feature/verbosity -> ,feature/verbosity,verbosity
-#  - viehture/bullshit -> ,viehture/bullshit,bullshit
-#
-re_docker_tag="^refs/(heads|tags)/v?([^/]+|[a-z]+/(.*))$"
-
 case "$GITHUB_EVENT_NAME" in
 	workflow_dispatch|schedule|release)
-		[[ "$GITHUB_REF" =~ $re_docker_tag ]]
-		if [ -n "${BASH_REMATCH[3]}" ]; then
-			TAG="${BASH_REMATCH[3]}"
-		else
-			TAG="${BASH_REMATCH[2]}"
-		fi
+		case "$GITHUB_REF" in
+			refs/tags/v*)
+				MODE=release
+				TAG=${GITHUB_REF#refs/tags/v}
+				;;
+			refs/heads/*)
+				MODE=snapshot
+				TAG=${GITHUB_REF#refs/heads/}
+				# Remove everything up to the first slash to remove prefixes like "feature/"
+				TAG=${TAG#*/}
+				;;
+			*)
+				echo "Unknown ref: $GITHUB_REF" >&2
+				false
+				;;
+		esac
 		mkimg
 		push
 		;;
diff --git a/build.bash b/build.bash
index 208b689..5b72e79 100755
--- a/build.bash
+++ b/build.bash
@@ -3,7 +3,7 @@
 set -exo pipefail
 
 IW2SRC="$1"
-export MODS_BRANCH="$2"
+export BUILD_MODE="${2:-release}"
 
 if [ -z "$IW2SRC" ]; then
 	cat <<EOF >&2
@@ -22,14 +22,14 @@ docker run --rm -i \
 	-v "${IW2SRC}:/iw2src:ro" \
 	-v "${BLDCTX}:/bldctx:ro" \
 	-v /var/run/docker.sock:/var/run/docker.sock \
-	-e MODS_BRANCH \
+	-e BUILD_MODE \
 	icinga/icingaweb2-builder bash <<EOF
 set -exo pipefail
 
 git -C /iw2src archive --prefix=iw2cp/icingaweb2/ HEAD |tar -xC /
 cd /iw2cp
 
-/bldctx/get-mods.sh "$MODS_BRANCH"
+/bldctx/get-mods.sh "$BUILD_MODE"
 /bldctx/composer.bash
 patch -d icingaweb2 -p0 < /bldctx/icingaweb2.patch
 
diff --git a/get-mods.sh b/get-mods.sh
index dc32e74..0b06849 100755
--- a/get-mods.sh
+++ b/get-mods.sh
@@ -2,7 +2,15 @@
 # Icinga Web 2 Docker image | (c) 2020 Icinga GmbH | GPLv2+
 set -exo pipefail
 
-BRANCH="$1"
+usage() {
+	cat >&2 <<EOF
+Usage: get-mods.sh <release|snapshot>
+
+  release:  download the latest release version of all external modules
+  snapshot: download a snapshot/development version of all external modules
+EOF
+	exit 1
+}
 
 get_tag () {
 	if git -C dockerweb2-temp tag |grep -qvFe -; then # ex. RCs
@@ -17,22 +25,25 @@ get_special () {
 		rm -rf dockerweb2-temp
 		git clone --bare "https://github.com/Icinga/${1}.git" dockerweb2-temp
 
-		case "$2" in
-			icingaweb2/modules/incubator)
+		case "$MODE" in
+			release)
 				REF="$(get_tag)"
 				;;
-			*)
-				if [ "$BRANCH" = master ] && [[ "$2" == icinga-php/* ]]; then
-					REF=snapshot/nightly
-				elif [ -n "$BRANCH" ] && git -C dockerweb2-temp show -s --oneline "$BRANCH"; then
-					REF="$BRANCH"
-				else
-					REF="$(get_tag)"
-
-					if [ "$2" = icingaweb2/modules/icingadb ] && [ "$REF" = 'v1.0.0-rc1' ]; then
-						REF=2c0662c420617712bd26234da550dcf8d4afcdb8 # v1.0.0-rc1+
-					fi
-				fi
+			snapshot)
+				case "$2" in
+					icingaweb2/modules/incubator)
+						# "HINT: Do NOT install the GIT master, it will not work!"
+						# https://github.com/Icinga/icingaweb2-module-incubator/blob/master/README.md
+						REF="$(get_tag)"
+						;;
+					icinga-php/*)
+						# Special branch that contains vendored dependencies missing in HEAD
+						REF=snapshot/nightly
+						;;
+					*)
+						REF=HEAD
+						;;
+				esac
 				;;
 		esac
 
@@ -53,6 +64,12 @@ get_mod () {
 	get_altname "icingaweb2-module-$1" "$1"
 }
 
+MODE="$1"
+case "$MODE" in
+	release|snapshot) ;;
+	*) usage ;;
+esac
+
 get_lib library ipl
 get_lib thirdparty vendor
 get_mod audit