diff --git a/auto_update_github_action.yml b/auto_update_github_action.yml
index b23b022..cd36700 100644
--- a/auto_update_github_action.yml
+++ b/auto_update_github_action.yml
@@ -35,9 +35,13 @@ jobs:
 
       - name: Download recommended whitelist
         run: bash ./get_recommended_whitelist.sh
+        env:
+          ALLOWLIST_URLS: ${{ vars.ALLOWLIST_URLS }}
 
       - name: Download recommended filters
         run: bash ./get_recommended_filters.sh
+        env:
+          BLOCKLIST_URLS: ${{ vars.BLOCKLIST_URLS }}
 
       - name: Delete old rules and lists
         run: |
diff --git a/download_lists.js b/download_lists.js
index 56e4a19..34e4413 100644
--- a/download_lists.js
+++ b/download_lists.js
@@ -1,74 +1,38 @@
 import { resolve } from "path";
 
-import { LIST_TYPE, PROCESSING_FILENAME } from "./lib/constants.js";
+import {
+  LIST_TYPE,
+  PROCESSING_FILENAME,
+  RECOMMENDED_ALLOWLIST_URLS,
+  RECOMMENDED_BLOCKLIST_URLS,
+  USER_DEFINED_ALLOWLIST_URLS,
+  USER_DEFINED_BLOCKLIST_URLS,
+} from "./lib/constants.js";
 import { downloadFiles } from "./lib/utils.js";
 
-const allowlistUrls = [
-  "https://raw.githubusercontent.com/im-sm/Pi-hole-Torrent-Blocklist/main/all-torrent-trackres.txt",
-  "https://raw.githubusercontent.com/AdguardTeam/HttpsExclusions/master/exclusions/banks.txt",
-  "https://raw.githubusercontent.com/hagezi/dns-blocklists/main/whitelist.txt",
-  "https://raw.githubusercontent.com/TogoFire-Home/AD-Settings/main/Filters/whitelist.txt",
-  "https://raw.githubusercontent.com/freekers/whitelist/master/domains/whitelist.txt",
-  "https://raw.githubusercontent.com/DandelionSprout/AdGuard-Home-Whitelist/master/whitelist.txt",
-  "https://raw.githubusercontent.com/AdguardTeam/AdGuardSDNSFilter/master/Filters/exclusions.txt",
-  "https://raw.githubusercontent.com/anudeepND/whitelist/master/domains/optional-list.txt",
-  "https://raw.githubusercontent.com/AdguardTeam/HttpsExclusions/master/exclusions/issues.txt",
-  "https://raw.githubusercontent.com/hagezi/dns-blocklists/main/whitelist-referral.txt",
-  "https://raw.githubusercontent.com/mawenjian/china-cdn-domain-whitelist/master/china-cdn-domain-whitelist.txt",
-  "https://raw.githubusercontent.com/notracking/hosts-blocklists-scripts/master/hostnames.whitelist.txt",
-  "https://raw.githubusercontent.com/AdguardTeam/HttpsExclusions/master/exclusions/mac.txt",
-  "https://raw.githubusercontent.com/boutetnico/url-shorteners/master/list.txt",
-  "https://raw.githubusercontent.com/AdguardTeam/HttpsExclusions/master/exclusions/windows.txt",
-  "https://raw.githubusercontent.com/Dogino/Discord-Phishing-URLs/main/official-domains.txt",
-  "https://raw.githubusercontent.com/ookangzheng/blahdns/master/hosts/whitelist.txt",
-  "https://raw.githubusercontent.com/AdguardTeam/HttpsExclusions/master/exclusions/android.txt",
-  "https://raw.githubusercontent.com/AdguardTeam/HttpsExclusions/master/exclusions/sensitive.txt",
-  "https://raw.githubusercontent.com/anudeepND/whitelist/master/domains/whitelist.txt",
-  "https://raw.githubusercontent.com/AdguardTeam/HttpsExclusions/master/exclusions/firefox.txt",
-  // Commented out because it whitelists sites including doubleclick.net and ad.atdmt.com
-  // https://raw.githubusercontent.com/anudeepND/whitelist/master/domains/referral-sites.txt,
-  // Uncomment the line below to use OISD's most commmonly whitelisted list
-  // https://local.oisd.nl/extract/commonly_whitelisted.php,
-];
-const blocklistUrls = [
-  "https://raw.githubusercontent.com/mullvad/dns-blocklists/main/output/doh/doh_adblock.txt",
-  "https://raw.githubusercontent.com/mullvad/dns-blocklists/main/output/doh/doh_gambling.txt",
-  "https://raw.githubusercontent.com/mullvad/dns-blocklists/main/output/doh/doh_privacy.txt",
-  "https://raw.githubusercontent.com/FadeMind/hosts.extras/master/add.Risk/hosts",
-  "https://adaway.org/hosts.txt",
-  "https://raw.githubusercontent.com/StevenBlack/hosts/master/hosts",
-];
+const allowlistUrls = USER_DEFINED_ALLOWLIST_URLS || RECOMMENDED_ALLOWLIST_URLS;
+const blocklistUrls = USER_DEFINED_BLOCKLIST_URLS || RECOMMENDED_BLOCKLIST_URLS;
 const listType = process.argv[2];
 
-const downloadAllowlists = async () => {
-  await downloadFiles(
-    resolve(`./${PROCESSING_FILENAME.ALLOWLIST}`),
-    allowlistUrls
-  );
+const downloadLists = async (filename, urls) => {
+  await downloadFiles(resolve(`./${filename}`), urls);
   console.log(
-    `Done. The ${PROCESSING_FILENAME.ALLOWLIST} file contains merged data from recommended allowlists.`
-  );
-};
-
-const downloadBlocklists = async () => {
-  await downloadFiles(
-    resolve(`./${PROCESSING_FILENAME.BLOCKLIST}`),
-    blocklistUrls
-  );
-  console.log(
-    `Done. The ${PROCESSING_FILENAME.BLOCKLIST} file contains merged data from recommended blocklists.`
+    `Done. The ${filename} file contains merged data from ${urls.length} list(s).`
   );
 };
 
 switch (listType) {
   case LIST_TYPE.ALLOWLIST: {
-    await downloadAllowlists();
+    await downloadLists(PROCESSING_FILENAME.ALLOWLIST, allowlistUrls);
     break;
   }
   case LIST_TYPE.BLOCKLIST: {
-    await downloadBlocklists();
+    await downloadLists(PROCESSING_FILENAME.BLOCKLIST, blocklistUrls);
     break;
   }
   default:
-    await Promise.all([downloadAllowlists(), downloadBlocklists()]);
+    await Promise.all([
+      downloadLists(PROCESSING_FILENAME.ALLOWLIST, allowlistUrls),
+      downloadLists(PROCESSING_FILENAME.BLOCKLIST, blocklistUrls),
+    ]);
 }
diff --git a/lib/constants.js b/lib/constants.js
index 9d5e124..6d1b31a 100644
--- a/lib/constants.js
+++ b/lib/constants.js
@@ -31,3 +31,46 @@ export const LIST_TYPE = {
   ALLOWLIST: "allowlist",
   BLOCKLIST: "blocklist",
 };
+
+export const USER_DEFINED_ALLOWLIST_URLS =
+  process.env.ALLOWLIST_URLS?.split("\n");
+
+export const USER_DEFINED_BLOCKLIST_URLS =
+  process.env.BLOCKLIST_URLS?.split("\n");
+
+export const RECOMMENDED_ALLOWLIST_URLS = [
+  "https://raw.githubusercontent.com/im-sm/Pi-hole-Torrent-Blocklist/main/all-torrent-trackres.txt",
+  "https://raw.githubusercontent.com/AdguardTeam/HttpsExclusions/master/exclusions/banks.txt",
+  "https://raw.githubusercontent.com/hagezi/dns-blocklists/main/whitelist.txt",
+  "https://raw.githubusercontent.com/TogoFire-Home/AD-Settings/main/Filters/whitelist.txt",
+  "https://raw.githubusercontent.com/freekers/whitelist/master/domains/whitelist.txt",
+  "https://raw.githubusercontent.com/DandelionSprout/AdGuard-Home-Whitelist/master/whitelist.txt",
+  "https://raw.githubusercontent.com/AdguardTeam/AdGuardSDNSFilter/master/Filters/exclusions.txt",
+  "https://raw.githubusercontent.com/anudeepND/whitelist/master/domains/optional-list.txt",
+  "https://raw.githubusercontent.com/AdguardTeam/HttpsExclusions/master/exclusions/issues.txt",
+  "https://raw.githubusercontent.com/hagezi/dns-blocklists/main/whitelist-referral.txt",
+  "https://raw.githubusercontent.com/mawenjian/china-cdn-domain-whitelist/master/china-cdn-domain-whitelist.txt",
+  "https://raw.githubusercontent.com/notracking/hosts-blocklists-scripts/master/hostnames.whitelist.txt",
+  "https://raw.githubusercontent.com/AdguardTeam/HttpsExclusions/master/exclusions/mac.txt",
+  "https://raw.githubusercontent.com/boutetnico/url-shorteners/master/list.txt",
+  "https://raw.githubusercontent.com/AdguardTeam/HttpsExclusions/master/exclusions/windows.txt",
+  "https://raw.githubusercontent.com/Dogino/Discord-Phishing-URLs/main/official-domains.txt",
+  "https://raw.githubusercontent.com/ookangzheng/blahdns/master/hosts/whitelist.txt",
+  "https://raw.githubusercontent.com/AdguardTeam/HttpsExclusions/master/exclusions/android.txt",
+  "https://raw.githubusercontent.com/AdguardTeam/HttpsExclusions/master/exclusions/sensitive.txt",
+  "https://raw.githubusercontent.com/anudeepND/whitelist/master/domains/whitelist.txt",
+  "https://raw.githubusercontent.com/AdguardTeam/HttpsExclusions/master/exclusions/firefox.txt",
+  // Commented out because it whitelists sites including doubleclick.net and ad.atdmt.com
+  // https://raw.githubusercontent.com/anudeepND/whitelist/master/domains/referral-sites.txt,
+  // Uncomment the line below to use OISD's most commmonly whitelisted list
+  // https://local.oisd.nl/extract/commonly_whitelisted.php,
+];
+
+export const RECOMMENDED_BLOCKLIST_URLS = [
+  "https://raw.githubusercontent.com/mullvad/dns-blocklists/main/output/doh/doh_adblock.txt",
+  "https://raw.githubusercontent.com/mullvad/dns-blocklists/main/output/doh/doh_gambling.txt",
+  "https://raw.githubusercontent.com/mullvad/dns-blocklists/main/output/doh/doh_privacy.txt",
+  "https://raw.githubusercontent.com/FadeMind/hosts.extras/master/add.Risk/hosts",
+  "https://adaway.org/hosts.txt",
+  "https://raw.githubusercontent.com/StevenBlack/hosts/master/hosts",
+];