diff --git a/.travis.yml b/.travis.yml
index 1c9849477..9003839b8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,6 +4,7 @@ env:
   matrix:
   - BROWSER=chromium EXT=zip
   - BROWSER=firefox EXT=xpi
+  - BROWSER=thunderbird EXT=xpi
 script: ./tools/make-${BROWSER}.sh ${TRAVIS_TAG}
 deploy:
   provider: releases
diff --git a/platform/thunderbird/manifest.json b/platform/thunderbird/manifest.json
new file mode 100644
index 000000000..84fcef1c2
--- /dev/null
+++ b/platform/thunderbird/manifest.json
@@ -0,0 +1,76 @@
+{
+  "applications": {
+    "gecko": {
+      "id": "uBlock0@raymondhill.net",
+      "strict_min_version": "65.0"
+    }
+  },
+  "author": "All uBlock Origin contributors",
+  "background": {
+    "page": "background.html"
+  },
+  "browser_action": {
+    "browser_style": false,
+    "default_icon": {
+      "16": "img/icon_16.png",
+      "32": "img/icon_32.png"
+    },
+    "default_title": "uBlock Origin",
+    "default_popup": "popup.html"
+  },
+  "content_scripts": [
+    {
+      "matches": [
+        "http://*/*",
+        "https://*/*",
+        "file://*/*"
+      ],
+      "js": [
+        "/js/vapi.js",
+        "/js/vapi-client.js",
+        "/js/contentscript.js"
+      ],
+      "run_at": "document_start",
+      "all_frames": true
+    },
+    {
+      "matches": [
+        "http://*/*",
+        "https://*/*"
+      ],
+      "js": [
+        "/js/scriptlets/subscriber.js"
+      ],
+      "run_at": "document_idle",
+      "all_frames": false
+    }
+  ],
+  "default_locale": "en",
+  "description": "__MSG_extShortDesc__",
+  "icons": {
+    "16": "img/ublock.svg",
+    "48": "img/ublock.svg",
+    "96": "img/ublock.svg"
+  },
+  "manifest_version": 2,
+  "name": "uBlock Origin",
+  "options_ui": {
+    "page": "dashboard.html",
+    "browser_style": false,
+    "open_in_tab": true
+  },
+  "permissions": [
+    "privacy",
+    "storage",
+    "tabs",
+    "webNavigation",
+    "webRequest",
+    "webRequestBlocking",
+    "<all_urls>"
+  ],
+  "short_name": "uBlock₀",
+  "version": "1.9.15.101",
+  "web_accessible_resources": [
+    "/web_accessible_resources/*"
+  ]
+}
diff --git a/platform/thunderbird/vapi-webrequest.js b/platform/thunderbird/vapi-webrequest.js
new file mode 100644
index 000000000..674351735
--- /dev/null
+++ b/platform/thunderbird/vapi-webrequest.js
@@ -0,0 +1,184 @@
+/*******************************************************************************
+
+    uBlock Origin - a browser extension to block requests.
+    Copyright (C) 2017-present Raymond Hill
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see {http://www.gnu.org/licenses/}.
+
+    Home: https://github.com/gorhill/uBlock
+*/
+
+// For background page
+
+'use strict';
+
+/******************************************************************************/
+
+(function() {
+
+    // https://github.com/gorhill/uBlock/issues/2950
+    // Firefox 56 does not normalize URLs to ASCII, uBO must do this itself.
+    // https://bugzilla.mozilla.org/show_bug.cgi?id=945240
+    const evalMustPunycode = function() {
+        return vAPI.webextFlavor.soup.has('firefox') &&
+               vAPI.webextFlavor.major < 57;
+    };
+
+    let mustPunycode = evalMustPunycode();
+
+    // The real actual webextFlavor value may not be set in stone, so listen
+    // for possible future changes.
+    window.addEventListener('webextFlavor', ( ) => {
+        mustPunycode = evalMustPunycode();
+    }, { once: true });
+
+    const denormalizeTypes = function(aa) {
+        if ( aa.length === 0 ) {
+            return Array.from(vAPI.net.validTypes);
+        }
+        const out = new Set();
+        let i = aa.length;
+        while ( i-- ) {
+            let type = aa[i];
+            if ( vAPI.net.validTypes.has(type) ) {
+                out.add(type);
+            }
+            if ( type === 'image' && vAPI.net.validTypes.has('imageset') ) {
+                out.add('imageset');
+            }
+            if ( type === 'sub_frame' ) {
+                out.add('object');
+            }
+        }
+        return Array.from(out);
+    };
+
+    const punycode = self.punycode;
+    const reAsciiHostname  = /^https?:\/\/[0-9a-z_.:@-]+[/?#]/;
+    const parsedURL = new URL('about:blank');
+
+    vAPI.net.normalizeDetails = function(details) {
+        if ( mustPunycode && !reAsciiHostname.test(details.url) ) {
+            parsedURL.href = details.url;
+            details.url = details.url.replace(
+                parsedURL.hostname,
+                punycode.toASCII(parsedURL.hostname)
+            );
+        }
+
+        const type = details.type;
+
+        // https://github.com/gorhill/uBlock/issues/1493
+        //   Chromium 49+/WebExtensions support a new request type: `ping`,
+        //   which is fired as a result of using `navigator.sendBeacon`.
+        if ( type === 'ping' ) {
+            details.type = 'beacon';
+            return;
+        }
+
+        if ( type === 'imageset' ) {
+            details.type = 'image';
+            return;
+        }
+
+        // https://github.com/uBlockOrigin/uBlock-issues/issues/345
+        //   Re-categorize an embedded object as a `sub_frame` if its
+        //   content type is that of a HTML document.
+        if ( type === 'object' && Array.isArray(details.responseHeaders) ) {
+            for ( const header of details.responseHeaders ) {
+                if ( header.name.toLowerCase() === 'content-type' ) {
+                    if ( header.value.startsWith('text/html') ) {
+                        details.type = 'sub_frame';
+                    }
+                    break;
+                }
+            }
+        }
+    };
+
+    vAPI.net.denormalizeFilters = function(filters) {
+        let urls = filters.urls || [ '<all_urls>' ];
+        if ( urls.indexOf('https://*/*') !== -1 ) {
+            urls = [ '<all_urls>' ];
+        }
+        let types = filters.types;
+        if ( Array.isArray(types) ) {
+            types = denormalizeTypes(types);
+        }
+        if (
+            (vAPI.net.validTypes.has('websocket')) &&
+            (types === undefined || types.indexOf('websocket') !== -1) &&
+            (urls.indexOf('<all_urls>') === -1)
+        ) {
+            if ( urls.indexOf('ws://*/*') === -1 ) {
+                urls.push('ws://*/*');
+            }
+            if ( urls.indexOf('wss://*/*') === -1 ) {
+                urls.push('wss://*/*');
+            }
+        }
+        return { types, urls };
+    };
+})();
+
+/******************************************************************************/
+
+// Related issues:
+// - https://github.com/gorhill/uBlock/issues/1327
+// - https://github.com/uBlockOrigin/uBlock-issues/issues/128
+// - https://bugzilla.mozilla.org/show_bug.cgi?id=1503721
+
+vAPI.net.onBeforeReady = (function() {
+    let pendings;
+
+    const handler = function(details) {
+        if ( pendings === undefined ) { return; }
+        if ( details.tabId < 0 ) { return; }
+
+        const pending = {
+            details: Object.assign({}, details),
+            resolve: undefined,
+            promise: undefined
+        };
+
+        pending.promise = new Promise(function(resolve) {
+            pending.resolve = resolve;
+        });
+
+        pendings.push(pending);
+
+        return pending.promise;
+    };
+
+    return {
+        start: function() {
+            pendings = [];
+            browser.webRequest.onBeforeRequest.addListener(
+                handler,
+                { urls: [ 'http://*/*', 'https://*/*' ] },
+                [ 'blocking' ]
+            );
+        },
+        stop: function(resolver) {
+            if ( pendings === undefined ) { return; }
+            for ( const pending of pendings ) {
+                vAPI.net.normalizeDetails(pending.details);
+                pending.resolve(resolver(pending.details));
+            }
+            pendings = undefined;
+        },
+    };
+})();
+
+/******************************************************************************/
diff --git a/tools/make-thunderbird.sh b/tools/make-thunderbird.sh
new file mode 100755
index 000000000..9854e5cbb
--- /dev/null
+++ b/tools/make-thunderbird.sh
@@ -0,0 +1,65 @@
+#!/usr/bin/env bash
+#
+# This script assumes a linux environment
+
+echo "*** uBlock0.thunderbird: Creating web store package"
+echo "*** uBlock0.thunderbird: Copying files"
+
+BLDIR=dist/build
+DES="$BLDIR"/uBlock0.thunderbird
+rm -rf $DES
+mkdir -p $DES
+
+bash ./tools/make-assets.sh $DES
+
+cp -R src/css                           $DES/
+cp -R src/img                           $DES/
+cp -R src/js                            $DES/
+cp -R src/lib                           $DES/
+cp -R src/_locales                      $DES/
+cp -R $DES/_locales/nb                  $DES/_locales/no
+cp src/*.html                           $DES/
+cp platform/chromium/*.js               $DES/js/
+cp platform/chromium/*.html             $DES/
+cp platform/chromium/*.json             $DES/
+cp LICENSE.txt                          $DES/
+
+cp platform/thunderbird/manifest.json      $DES/
+cp platform/thunderbird/vapi-webrequest.js $DES/js/
+cp platform/firefox/vapi-usercss.js        $DES/js/
+
+echo "*** uBlock0.thunderbird: concatenating content scripts"
+cat $DES/js/vapi-usercss.js > /tmp/contentscript.js
+echo >> /tmp/contentscript.js
+grep -v "^'use strict';$" $DES/js/vapi-usercss.real.js >> /tmp/contentscript.js
+echo >> /tmp/contentscript.js
+grep -v "^'use strict';$" $DES/js/contentscript.js >> /tmp/contentscript.js
+mv /tmp/contentscript.js $DES/js/contentscript.js
+rm $DES/js/vapi-usercss.js
+rm $DES/js/vapi-usercss.real.js
+rm $DES/js/vapi-usercss.pseudo.js
+
+# Firefox/webext-specific
+rm $DES/img/icon_128.png
+
+echo "*** uBlock0.thunderbird: Generating web accessible resources..."
+cp -R src/web_accessible_resources $DES/
+python3 tools/import-war.py $DES/
+
+echo "*** uBlock0.thunderbird: Generating meta..."
+python tools/make-firefox-meta.py $DES/
+
+if [ "$1" = all ]; then
+    echo "*** uBlock0.thunderbird: Creating package..."
+    pushd $DES > /dev/null
+    zip ../$(basename $DES).xpi -qr *
+    popd > /dev/null
+elif [ -n "$1" ]; then
+    echo "*** uBlock0.thunderbird: Creating versioned package..."
+    pushd $DES > /dev/null
+    zip ../$(basename $DES).xpi -qr *
+    popd > /dev/null
+    mv "$BLDIR"/uBlock0.thunderbird.xpi "$BLDIR"/uBlock0_"$1".thunderbird.xpi
+fi
+
+echo "*** uBlock0.thunderbird: Package done."