diff --git a/package.json b/package.json
index 948ca1b993..f0ac4c6629 100644
--- a/package.json
+++ b/package.json
@@ -45,6 +45,7 @@
     "prepare-adhoc-build": "node scripts/prepare_adhoc_build.js",
     "prepare-adhoc-version": "node scripts/prepare_tagged_version.js adhoc",
     "prepare-staging-build": "node scripts/prepare_staging_build.js",
+    "prepare-linux-build": "node scripts/prepare_linux_build.js",
     "test": "run-s test-node test-electron test-lint-intl test-eslint",
     "test-electron": "node ts/scripts/test-electron.js",
     "test-release": "node ts/scripts/test-release.js",
diff --git a/reproducible-builds/build.sh b/reproducible-builds/build.sh
index e4667aa1d9..40b802f9cc 100755
--- a/reproducible-builds/build.sh
+++ b/reproducible-builds/build.sh
@@ -3,7 +3,15 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 
 # Usage:
-# ./build.sh [ dev (default) | public (prod and beta builds) | alpha | test | staging ] [ Build timestamp override. Defaults to latest git commit or 1. ]
+# ./build.sh [ dev (default) | public (prod and beta builds) | alpha | test | staging ]
+# Env vars:
+# SOURCE_DATE_EPOCH: Build timestamp override. Defaults to latest git commit or 1.
+# SKIP_DOCKER_BUILD: To support docker build cache during actions.
+# BUILD_TARGETS: Override build targets. Empty default results in deb.
+
+# Examples:
+# ./build.sh public
+# SOURCE_DATE_EPOCH=123 ./build.sh test
 
 # First we prepare the docker container in which our build scripts will run. This container includes
 # all build dependencies at specific versions.
@@ -19,9 +27,9 @@ cd ..
 
 # Prepare the timestamp of the actual build based on the latest git commit.
 source_date_epoch=1
-if [ "$2" != "" ]; then
+if [ -n "${SOURCE_DATE_EPOCH}" ]; then
   echo "Using override timestamp for SOURCE_DATE_EPOCH."
-  source_date_epoch=$(($2))
+  source_date_epoch="${SOURCE_DATE_EPOCH}"
 else
   git_timestamp=$(git log -1 --pretty=%ct)
   if [ "${git_timestamp}" != "" ]; then
@@ -45,4 +53,5 @@ docker run --rm \
   -e NPM_CONFIG_CACHE=/tmp/.npm-cache \
   -e PNPM_HOME=/tmp/.pnpm-home \
   -e SOURCE_DATE_EPOCH=$source_date_epoch \
+  -e BUILD_TARGETS=$BUILD_TARGETS \
   signal-desktop $1
diff --git a/reproducible-builds/docker-entrypoint.sh b/reproducible-builds/docker-entrypoint.sh
index c9cfb14824..118ef910c5 100644
--- a/reproducible-builds/docker-entrypoint.sh
+++ b/reproducible-builds/docker-entrypoint.sh
@@ -66,4 +66,8 @@ else
   exit 1
 fi
 
+if [ "${BUILD_TARGETS}" != "" ]; then
+  pnpm run prepare-linux-build $BUILD_TARGETS
+fi
+
 pnpm run build-linux
diff --git a/scripts/prepare_linux_build.js b/scripts/prepare_linux_build.js
new file mode 100644
index 0000000000..c41bdde6a5
--- /dev/null
+++ b/scripts/prepare_linux_build.js
@@ -0,0 +1,30 @@
+// Copyright 2025 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+const fs = require('node:fs');
+const _ = require('lodash');
+
+const TARGETS = new Set(['appimage', 'deb']);
+
+const targets = (process.argv[2] || '').split(',');
+if (
+  targets.length === 0 ||
+  !targets.every(target => TARGETS.has(target.toLowerCase()))
+) {
+  console.error(
+    `Invalid linux targets ${targets}. Valid options: ${[...TARGETS]}`
+  );
+  process.exit(1);
+}
+
+const { default: packageJson } = require('./packageJson.js');
+
+console.log('prepare_linux_build: updating package.json');
+
+// ------
+
+_.set(packageJson, 'build.linux.target', targets);
+
+// -------
+
+fs.writeFileSync('./package.json', JSON.stringify(packageJson, null, '  '));