diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b810293..8457ab3 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -6,85 +6,86 @@
 image: node:lts
 
 stages:
-    - test
-    - build
-    - release
-
-before_script:
-    - yarn install --immutable
+  - test
+  - build
+  - release
 
 cache: &global_cache
-    paths:
-        - .yarn/cache
+  paths:
+    - .yarn/cache
 
 lint:
-    stage: test
-    script:
-        - yarn lint
-    cache:
-        <<: *global_cache
+  stage: test
+  before_script:
+    - yarn install --immutable
+  script:
+    - yarn lint
+  cache:
+    <<: *global_cache
 
 reuse:
-    stage: test
-    image:
-        name: fsfe/reuse:latest
-        entrypoint: [""]
-    before_script: []
-    script:
-        - reuse lint
+  stage: test
+  image:
+    name: fsfe/reuse:latest
+    entrypoint: ['']
+  script:
+    - reuse lint
 
 build:
-    stage: build
-    script:
-        - yarn build
-        - mv dist darkness-dependent-vision
-    cache:
-        <<: *global_cache
-    artifacts:
-        paths:
-            - darkness-dependent-vision
-        expire_in: 1 week
+  stage: build
+  before_script:
+    - yarn install --immutable
+    - if [[ ! -z ${CI_COMMIT_TAG+x} ]]; then export NODE_ENV=production; fi
+  script:
+    - yarn build
+    - mv dist darkness-dependent-vision
+  cache:
+    <<: *global_cache
+  artifacts:
+    paths:
+      - darkness-dependent-vision
+    expire_in: 1 week
 
 .release-template: &release-template
-    stage: release
-    before_script:
-        - yarn install
-        - apt update
-        - apt install --yes jq
-        - REPOSITORY_URL=$(echo "${CI_REPOSITORY_URL}" | sed -e "s|gitlab-ci-token:.*@|${RELEASE_TOKEN}:${RELEASE_TOKEN_SECRET}@|g")
-        - git remote set-url origin $REPOSITORY_URL
-        - git config user.name $GITLAB_USER_LOGIN
-        - git config user.email $GITLAB_USER_EMAIL
-        - git branch -D ci-processing || true
-        - git checkout -b ci-processing
-    cache:
-        <<: *global_cache
-    script: |
-        yarn bump-version --release=${RELEASE_TYPE}
-        RELEASE_VERSION=$(jq -r '.version' < package.json)
-        git add package.json src/module.json
-        git --no-pager diff
-        git commit -m "release version ${RELEASE_VERSION}"
-        git tag -f latest
-        git tag -f ${RELEASE_VERSION}
-        git push origin ci-processing:${CI_BUILD_REF_NAME}
-        git push origin latest -f
-        git push origin ${RELEASE_VERSION}
-    only:
-        - master
-    when: manual
+  stage: release
+  before_script:
+    - yarn install --immutable
+    - apt update
+    - apt install --yes jq
+    - REPOSITORY_URL=$(echo "${CI_REPOSITORY_URL}" | sed -e "s|gitlab-ci-token:.*@|${RELEASE_TOKEN}:${RELEASE_TOKEN_SECRET}@|g")
+    - git remote set-url origin $REPOSITORY_URL
+    - git config user.name $GITLAB_USER_LOGIN
+    - git config user.email $GITLAB_USER_EMAIL
+    - git branch -D ci-processing || true
+    - git checkout -b ci-processing
+  cache:
+    <<: *global_cache
+  script: |
+    yarn bump-version --release=${RELEASE_TYPE}
+    RELEASE_VERSION=$(jq -r '.version' < package.json)
+    git add package.json src/module.json
+    git --no-pager diff
+    git commit -m "release version ${RELEASE_VERSION}"
+    git tag -f latest
+    git tag -f ${RELEASE_VERSION}
+    git push origin ci-processing:${CI_BUILD_REF_NAME}
+    git push origin latest -f
+    git push origin ${RELEASE_VERSION}
+  only:
+    - master
+  when: manual
 
 release-patch:
-    variables:
-        RELEASE_TYPE: patch
-    <<: *release-template
+  variables:
+    RELEASE_TYPE: patch
+  <<: *release-template
 
 release-minor:
-    variables:
-        RELEASE_TYPE: minor
-    <<: *release-template
+  variables:
+    RELEASE_TYPE: minor
+  <<: *release-template
 
 release-major:
-    variables:
-        RELEASE_TYPE: major
-    <<: *release-template
+  variables:
+    RELEASE_TYPE: major
+  <<: *release-template
diff --git a/package.json b/package.json
index 340a58e..c82ea51 100644
--- a/package.json
+++ b/package.json
@@ -27,7 +27,7 @@
     "bump-version": "gulp bumpVersion",
     "lint": "eslint --ext .js .",
     "lint:fix": "eslint --ext .js --fix .",
-    "format": "prettier --write \"./**/*.(js|json|css)\"",
+    "format": "prettier --write \"./**/*.(js|json|css|yml)\"",
     "postinstall": "husky install"
   },
   "devDependencies": {
@@ -42,11 +42,13 @@
     "lint-staged": "11.2.6",
     "prettier": "2.4.1",
     "rollup": "2.58.3",
+    "rollup-plugin-sourcemaps": "^0.6.3",
+    "rollup-plugin-terser": "^7.0.2",
     "semver": "7.3.5",
     "yargs": "17.2.1"
   },
   "lint-staged": {
     "*.(js)": "eslint --fix",
-    "*.(json|css)": "prettier --write"
+    "*.(json|css|yml)": "prettier --write"
   }
 }
diff --git a/rollup.config.js b/rollup.config.js
index 41c50c6..ca01e81 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -2,6 +2,9 @@
 //
 // SPDX-License-Identifier: MIT
 
+const sourcemaps = require('rollup-plugin-sourcemaps');
+const { terser } = require('rollup-plugin-terser');
+
 module.exports = {
   input: 'src/module/darkness-dependent-vision.js',
   output: {
@@ -9,4 +12,5 @@ module.exports = {
     format: 'es',
     sourcemap: true,
   },
+  plugins: [sourcemaps(), process.env.NODE_ENV === 'production' && terser()],
 };
diff --git a/yarn.lock b/yarn.lock
index 826b226..75967b9 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -5,7 +5,7 @@ __metadata:
   version: 4
   cacheKey: 7
 
-"@babel/code-frame@npm:^7.0.0":
+"@babel/code-frame@npm:^7.0.0, @babel/code-frame@npm:^7.10.4":
   version: 7.15.8
   resolution: "@babel/code-frame@npm:7.15.8"
   dependencies:
@@ -77,6 +77,19 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@rollup/pluginutils@npm:^3.0.9":
+  version: 3.1.0
+  resolution: "@rollup/pluginutils@npm:3.1.0"
+  dependencies:
+    "@types/estree": 0.0.39
+    estree-walker: ^1.0.1
+    picomatch: ^2.2.2
+  peerDependencies:
+    rollup: ^1.20.0||^2.0.0
+  checksum: 45da6411e045d1b034242a8144f4a5e8c02ff1b68a2e0857807f5bb4b091c416f2015e075057f0f0dec200e7b35efe6ed4e301b43e365cedea09192f01a6839b
+  languageName: node
+  linkType: hard
+
 "@tootallnate/once@npm:1":
   version: 1.1.2
   resolution: "@tootallnate/once@npm:1.1.2"
@@ -84,6 +97,20 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@types/estree@npm:0.0.39":
+  version: 0.0.39
+  resolution: "@types/estree@npm:0.0.39"
+  checksum: 43e5361de39969def145f32f4599391ab13055ec94841f1633a7cfe10f0e8a940ebf0e9a4b2770454a6bddd034b57e7e0d51a4d565cb2714ee2accf10a7718be
+  languageName: node
+  linkType: hard
+
+"@types/node@npm:*":
+  version: 16.11.6
+  resolution: "@types/node@npm:16.11.6"
+  checksum: 52890a089f89ca9f20d6022c65aa747954040835436f1ceca62bdba1e2e604a86f8a2bbc4a5d54c975834092bb22f8e23832cd6b2d1b0abc0249e9f5035d86b4
+  languageName: node
+  linkType: hard
+
 "@types/parse-json@npm:^4.0.0":
   version: 4.0.0
   resolution: "@types/parse-json@npm:4.0.0"
@@ -846,6 +873,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"commander@npm:^2.20.0":
+  version: 2.20.3
+  resolution: "commander@npm:2.20.3"
+  checksum: b73428e97de7624323f81ba13f8ed9271de487017432d18b4da3f07cfc528ad754bbd199004bd5d14e0ccd67d1fdfe0ec8dbbd4c438b401df3c4cc387bfd1daa
+  languageName: node
+  linkType: hard
+
 "commander@npm:^8.2.0":
   version: 8.2.0
   resolution: "commander@npm:8.2.0"
@@ -968,6 +1002,8 @@ __metadata:
     lint-staged: 11.2.6
     prettier: 2.4.1
     rollup: 2.58.3
+    rollup-plugin-sourcemaps: ^0.6.3
+    rollup-plugin-terser: ^7.0.2
     semver: 7.3.5
     yargs: 17.2.1
   languageName: unknown
@@ -1397,6 +1433,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"estree-walker@npm:^1.0.1":
+  version: 1.0.1
+  resolution: "estree-walker@npm:1.0.1"
+  checksum: 85e7cee763e9125a7d8a947b3a06a8b9282873936df220dd0d791d9b3315e45e40ab096b43ba71bdc99140c11a6d23fdcf686642dc119a7b2d6181004fdb24d2
+  languageName: node
+  linkType: hard
+
 "esutils@npm:^2.0.2":
   version: 2.0.3
   resolution: "esutils@npm:2.0.3"
@@ -2556,6 +2599,17 @@ fsevents@~2.3.2:
   languageName: node
   linkType: hard
 
+"jest-worker@npm:^26.2.1":
+  version: 26.6.2
+  resolution: "jest-worker@npm:26.6.2"
+  dependencies:
+    "@types/node": "*"
+    merge-stream: ^2.0.0
+    supports-color: ^7.0.0
+  checksum: 5eb349833b5e9750ce8700388961dfd5d5e207c913122221e418e48b9cda3c17b0fb418f6a90f1614cfdc3ca836158b720c5dc1de82cb1e708266b4d76e31a38
+  languageName: node
+  linkType: hard
+
 "js-tokens@npm:^4.0.0":
   version: 4.0.0
   resolution: "js-tokens@npm:4.0.0"
@@ -3459,7 +3513,7 @@ fsevents@~2.3.2:
   languageName: node
   linkType: hard
 
-"picomatch@npm:^2.2.3":
+"picomatch@npm:^2.2.2, picomatch@npm:^2.2.3":
   version: 2.3.0
   resolution: "picomatch@npm:2.3.0"
   checksum: 80113a0fb70cfa62730d5aa3fd3d45b76bf3985f8494080ab2de1cc1fa3ba96d77990c7553a81401e16c51c0eb19c27cf5bc94f2196155090f26c8a167968001
@@ -3596,6 +3650,15 @@ fsevents@~2.3.2:
   languageName: node
   linkType: hard
 
+"randombytes@npm:^2.1.0":
+  version: 2.1.0
+  resolution: "randombytes@npm:2.1.0"
+  dependencies:
+    safe-buffer: ^5.1.0
+  checksum: ede2693af09732ceab1c273dd70db787f34a7b8d95bab13f1aca763483c0113452a78e53d61ff18d393dcea586d388e01f198a5132a4a85cebba31ec54164b75
+  languageName: node
+  linkType: hard
+
 "read-pkg-up@npm:^1.0.1":
   version: 1.0.1
   resolution: "read-pkg-up@npm:1.0.1"
@@ -3831,6 +3894,36 @@ fsevents@~2.3.2:
   languageName: node
   linkType: hard
 
+"rollup-plugin-sourcemaps@npm:^0.6.3":
+  version: 0.6.3
+  resolution: "rollup-plugin-sourcemaps@npm:0.6.3"
+  dependencies:
+    "@rollup/pluginutils": ^3.0.9
+    source-map-resolve: ^0.6.0
+  peerDependencies:
+    "@types/node": ">=10.0.0"
+    rollup: ">=0.31.2"
+  peerDependenciesMeta:
+    "@types/node":
+      optional: true
+  checksum: 73e8d02fa8ade508fb0b9c74ec273aad557d1e7f32a71c156df85337cc277834922734601233103f7a6e398fbddd53bc9105288f7b54d5e3b6dd88c2a882079e
+  languageName: node
+  linkType: hard
+
+"rollup-plugin-terser@npm:^7.0.2":
+  version: 7.0.2
+  resolution: "rollup-plugin-terser@npm:7.0.2"
+  dependencies:
+    "@babel/code-frame": ^7.10.4
+    jest-worker: ^26.2.1
+    serialize-javascript: ^4.0.0
+    terser: ^5.0.0
+  peerDependencies:
+    rollup: ^2.0.0
+  checksum: 553cc21efcea3e4d46c61fbd41cb4a82a3ab8e02ae4ce7c03f9248dea93e5a91c3624e2271490ee05b2bb481568305733b496d968d3ac9c99b777a588a336f01
+  languageName: node
+  linkType: hard
+
 "rollup@npm:2.58.3":
   version: 2.58.3
   resolution: "rollup@npm:2.58.3"
@@ -3920,6 +4013,15 @@ fsevents@~2.3.2:
   languageName: node
   linkType: hard
 
+"serialize-javascript@npm:^4.0.0":
+  version: 4.0.0
+  resolution: "serialize-javascript@npm:4.0.0"
+  dependencies:
+    randombytes: ^2.1.0
+  checksum: f17305aaabab9ae443505d1bf477c13b09adb7031c397d18400bec16f43f788febdd3311ca6043fdebd1d446cfa70a5804ef7268da54351dec51080f56d52fa9
+  languageName: node
+  linkType: hard
+
 "set-blocking@npm:^2.0.0, set-blocking@npm:~2.0.0":
   version: 2.0.0
   resolution: "set-blocking@npm:2.0.0"
@@ -4061,6 +4163,26 @@ fsevents@~2.3.2:
   languageName: node
   linkType: hard
 
+"source-map-resolve@npm:^0.6.0":
+  version: 0.6.0
+  resolution: "source-map-resolve@npm:0.6.0"
+  dependencies:
+    atob: ^2.1.2
+    decode-uri-component: ^0.2.0
+  checksum: 9bbd2656937ce422f1526026638a91dacba0822f1ab954ac34728c9b4f2960dbfc22a8463af9fbf74f28f3722263444df79b2b5ffa07de07dbcda2ec5a8c7513
+  languageName: node
+  linkType: hard
+
+"source-map-support@npm:~0.5.20":
+  version: 0.5.20
+  resolution: "source-map-support@npm:0.5.20"
+  dependencies:
+    buffer-from: ^1.0.0
+    source-map: ^0.6.0
+  checksum: 2c5821ee94732b2ddbb1e1d9e61ed76ef00f72415fa686ab96d5f5c711789d55424866fa7d6c493beea380e44418053d86ec490b82c101008eac311463da84a9
+  languageName: node
+  linkType: hard
+
 "source-map-url@npm:^0.4.0":
   version: 0.4.1
   resolution: "source-map-url@npm:0.4.1"
@@ -4075,6 +4197,20 @@ fsevents@~2.3.2:
   languageName: node
   linkType: hard
 
+"source-map@npm:^0.6.0":
+  version: 0.6.1
+  resolution: "source-map@npm:0.6.1"
+  checksum: 8647829a0611724114022be455ca1c8a2c8ae61df81c5b3667d9b398207226a1e21174fb7bbf0b4dbeb27ac358222afb5a14f1c74a62a62b8883b012e5eb1270
+  languageName: node
+  linkType: hard
+
+"source-map@npm:~0.7.2":
+  version: 0.7.3
+  resolution: "source-map@npm:0.7.3"
+  checksum: 351ce26ffa1ebf203660c0d70d7566c81e65d2d994d1c2d94da140808e02da34961673ce12ecea9b40797b96fbeb8c70bf71a4ad9f779f1a4fdbba75530bb386
+  languageName: node
+  linkType: hard
+
 "sparkles@npm:^1.0.0":
   version: 1.0.1
   resolution: "sparkles@npm:1.0.1"
@@ -4299,7 +4435,7 @@ fsevents@~2.3.2:
   languageName: node
   linkType: hard
 
-"supports-color@npm:^7.1.0":
+"supports-color@npm:^7.0.0, supports-color@npm:^7.1.0":
   version: 7.2.0
   resolution: "supports-color@npm:7.2.0"
   dependencies:
@@ -4332,6 +4468,19 @@ fsevents@~2.3.2:
   languageName: node
   linkType: hard
 
+"terser@npm:^5.0.0":
+  version: 5.9.0
+  resolution: "terser@npm:5.9.0"
+  dependencies:
+    commander: ^2.20.0
+    source-map: ~0.7.2
+    source-map-support: ~0.5.20
+  bin:
+    terser: bin/terser
+  checksum: 7603e5a3dc0317cc4b3251e855aa90ef397b03780a1d0d747b20b832d857b50d4c017b1342007f562e20e3e538044daa71e5addd5ab6aad64ee926c5d4b0c88f
+  languageName: node
+  linkType: hard
+
 "text-table@npm:^0.2.0":
   version: 0.2.0
   resolution: "text-table@npm:0.2.0"