diff --git a/distro-packages/Arch-Linux/PKGBUILD b/distro-packages/Arch-Linux/PKGBUILD
index 435cdd0..87c491c 100644
--- a/distro-packages/Arch-Linux/PKGBUILD
+++ b/distro-packages/Arch-Linux/PKGBUILD
@@ -1,7 +1,7 @@
 # Maintainer: Storm Dragon <storm_dragon@stormux.org>
 
 pkgname=cthulhu
-pkgver=2025.12.27
+pkgver=2025.12.27-testing
 pkgrel=1
 pkgdesc="Desktop-agnostic screen reader with plugin system, forked from Orca"
 url="https://git.stormux.org/storm/cthulhu"
diff --git a/meson.build b/meson.build
index 63e7234..6514a90 100644
--- a/meson.build
+++ b/meson.build
@@ -1,5 +1,5 @@
 project('cthulhu',
-  version: '2025.12.27',
+  version: '2025.12.27-testing',
   meson_version: '>= 1.0.0',
 )
 
diff --git a/set-version.sh b/set-version.sh
index c3eb7c9..27aafaa 100755
--- a/set-version.sh
+++ b/set-version.sh
@@ -2,18 +2,60 @@
 set -euo pipefail
 
 scriptDir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-newVersion="${1:-}"
+dateInput="${1:-}"
+branchInput="${2:-}"
 
-if [[ -z "$newVersion" ]]; then
-  newVersion="$(date +%Y.%m.%d)"
+if [[ -z "$dateInput" ]]; then
+  dateInput="$(date +%Y.%m.%d)"
 fi
 
-if [[ ! "$newVersion" =~ ^[0-9]{4}\.[0-9]{2}\.[0-9]{2}$ ]]; then
-  echo "Usage: $(basename "$0") [YYYY.MM.DD]" >&2
-  echo "Error: version must match YYYY.MM.DD" >&2
+if [[ ! "$dateInput" =~ ^([0-9]{4}\.[0-9]{2}\.[0-9]{2})(-([A-Za-z0-9._-]+))?$ ]]; then
+  echo "Usage: $(basename "$0") [YYYY.MM.DD[-branch]] [branch]" >&2
+  echo "Error: version must match YYYY.MM.DD or YYYY.MM.DD-branch" >&2
   exit 1
 fi
 
+datePart="${BASH_REMATCH[1]}"
+suffixPart="${BASH_REMATCH[3]}"
+
+if [[ -n "$suffixPart" && -n "$branchInput" ]]; then
+  echo "Warning: branch argument ignored because suffix was provided in version." >&2
+  branchInput=""
+fi
+
+if [[ -z "$suffixPart" ]]; then
+  if [[ -z "$branchInput" ]]; then
+    branchInput="$(git -C "$scriptDir" branch --show-current 2>/dev/null || true)"
+  fi
+
+  if [[ "$branchInput" == "HEAD" ]]; then
+    branchInput=""
+  fi
+
+  if [[ -n "$branchInput" ]]; then
+    branchName="$(printf '%s' "$branchInput" | sed 's/[^A-Za-z0-9._-]/-/g')"
+    branchName="${branchName#-}"
+    branchName="${branchName%-}"
+    suffixPart="$branchName"
+  fi
+fi
+
+pythonVersion="$datePart"
+fullVersion="$datePart"
+if [[ -n "$suffixPart" ]]; then
+  fullVersion="${fullVersion}-${suffixPart}"
+fi
+
+if [[ ! "$fullVersion" =~ ^[0-9]{4}\.[0-9]{2}\.[0-9]{2}(-[A-Za-z0-9._-]+)?$ ]]; then
+  echo "Error: generated version '${fullVersion}' is invalid" >&2
+  exit 1
+fi
+
+codeNameValue=""
+if [[ -n "$suffixPart" ]]; then
+  codeNameValue="$suffixPart"
+fi
+
 cthulhuVersionFile="${scriptDir}/src/cthulhu/cthulhuVersion.py"
 mesonFile="${scriptDir}/meson.build"
 pkgbuildFile="${scriptDir}/distro-packages/Arch-Linux/PKGBUILD"
@@ -25,20 +67,27 @@ for path in "$cthulhuVersionFile" "$mesonFile" "$pkgbuildFile"; do
   fi
 done
 
-sed -i "s/^version = \".*\"/version = \"${newVersion}\"/" "$cthulhuVersionFile"
-sed -i "s/^  version: '.*',/  version: '${newVersion}',/" "$mesonFile"
-sed -i "s/^pkgver=.*/pkgver=${newVersion}/" "$pkgbuildFile"
+sed -i "s/^version = \".*\"/version = \"${pythonVersion}\"/" "$cthulhuVersionFile"
+if [[ -n "$codeNameValue" ]]; then
+  sed -i "s/^codeName = \".*\"/codeName = \"${codeNameValue}\"/" "$cthulhuVersionFile"
+fi
+sed -i "s/^  version: '.*',/  version: '${fullVersion}',/" "$mesonFile"
+sed -i "s/^pkgver=.*/pkgver=${fullVersion}/" "$pkgbuildFile"
 sed -i "s/^pkgrel=.*/pkgrel=1/" "$pkgbuildFile"
 
-if ! rg -q "^version = \"${newVersion}\"" "$cthulhuVersionFile"; then
+if ! rg -q "^version = \"${pythonVersion}\"" "$cthulhuVersionFile"; then
   echo "Error: Failed to update ${cthulhuVersionFile}" >&2
   exit 1
 fi
-if ! rg -q "^  version: '${newVersion}'," "$mesonFile"; then
+if [[ -n "$codeNameValue" ]] && ! rg -q "^codeName = \"${codeNameValue}\"" "$cthulhuVersionFile"; then
+  echo "Error: Failed to update codeName in ${cthulhuVersionFile}" >&2
+  exit 1
+fi
+if ! rg -q "^  version: '${fullVersion}'," "$mesonFile"; then
   echo "Error: Failed to update ${mesonFile}" >&2
   exit 1
 fi
-if ! rg -q "^pkgver=${newVersion}$" "$pkgbuildFile"; then
+if ! rg -q "^pkgver=${fullVersion}$" "$pkgbuildFile"; then
   echo "Error: Failed to update ${pkgbuildFile}" >&2
   exit 1
 fi
@@ -47,7 +96,7 @@ if ! rg -q "^pkgrel=1$" "$pkgbuildFile"; then
   exit 1
 fi
 
-echo "Updated version to ${newVersion} in:" \
+echo "Updated version to ${fullVersion} in:" \
   "${cthulhuVersionFile}" \
   "${mesonFile}" \
   "${pkgbuildFile}"