diff --git a/.tx/backport b/.tx/backport
new file mode 100644
index 000000000..edd984181
--- /dev/null
+++ b/.tx/backport
@@ -0,0 +1 @@
+stable21.1
diff --git a/generate-localizable-strings-file.sh b/generate-localizable-strings-file.sh
index 749885725..538c76206 100755
--- a/generate-localizable-strings-file.sh
+++ b/generate-localizable-strings-file.sh
@@ -6,9 +6,59 @@
 # generate-localizable-strings-file.sh
 
 echo 'Generating Localizable.strings file...'
-cd NextcloudTalk
-genstrings -o en.lproj -SwiftUI *.m *.swift ../ShareExtension/*.m ../ShareExtension/*.swift ../NotificationServiceExtension/*.m ../BroadcastUploadExtension/*.swift ../TalkIntents/*.swift ../ThirdParty/SlackTextViewController/Source/*.m
-iconv -f UTF-16 -t UTF-8 en.lproj/Localizable.strings > en.lproj/Localizable-utf8.strings
-mv en.lproj/Localizable-utf8.strings en.lproj/Localizable.strings
+
+STABLE_BRANCH=$(<.tx/backport)
+
+FILE_PATHS=(
+  "NextcloudTalk/*.m"
+  "NextcloudTalk/*.swift"
+  "ShareExtension/*.m"
+  "ShareExtension/*.swift"
+  "NotificationServiceExtension/*.m"
+  "BroadcastUploadExtension/*.swift"
+  "TalkIntents/*.swift"
+  "ThirdParty/SlackTextViewController/Source/*.m"
+)
+
+STABLE_BRANCH_FILE_PATHS=(
+  "NextcloudTalk/*.m"
+  "NextcloudTalk/*.swift"
+  "ShareExtension/*.m"
+  "ShareExtension/*.swift"
+  "NotificationServiceExtension/*.m"
+  "BroadcastUploadExtension/*.swift"
+  "TalkIntents/*.swift"
+  "ThirdParty/SlackTextViewController/Source/*.m"
+)
+
+CURRENT_BRANCH=$(git branch --show-current)
+
+if [ "$CURRENT_BRANCH" != $STABLE_BRANCH ]; then
+  echo "Not on $STABLE_BRANCH branch, cloning $STABLE_BRANCH branch"
+
+  REMOTE_URL=$(git config --get remote.origin.url)
+  if [ -z "$REMOTE_URL" ]; then
+  	echo "No remote URL found. Please check your git config."
+  	exit 1
+  fi
+
+  git clone --branch $STABLE_BRANCH --single-branch --depth 1 $REMOTE_URL $STABLE_BRANCH
+  cd $STABLE_BRANCH
+  git submodule update --init
+  cd ..
+
+  STABLE_FILE_PATHS=()
+  for path in "${STABLE_BRANCH_FILE_PATHS[@]}"; do
+  	STABLE_FILE_PATHS+=("$STABLE_BRANCH/$path")
+  done
+
+else
+  echo "On $STABLE_BRANCH branch"
+fi
+
+genstrings -o NextcloudTalk/en.lproj -SwiftUI ${FILE_PATHS[@]} ${STABLE_FILE_PATHS[@]}
+iconv -f UTF-16 -t UTF-8 NextcloudTalk/en.lproj/Localizable.strings > NextcloudTalk/en.lproj/Localizable-utf8.strings
+mv NextcloudTalk/en.lproj/Localizable-utf8.strings NextcloudTalk/en.lproj/Localizable.strings
+rm -rf "$STABLE_BRANCH"
 echo 'Localizable.strings file generated!'