diff --git a/package.json b/package.json
index 45f99265..57d8513f 100644
--- a/package.json
+++ b/package.json
@@ -38,7 +38,7 @@
     "clean": "rimraf lib webapp electron_app/dist",
     "build": "yarn clean && yarn build:genfiles && yarn build:compile && yarn build:types && yarn build:bundle",
     "build-stats": "yarn clean && yarn build:genfiles && yarn build:compile && yarn build:types && yarn build:bundle-stats",
-    "build:jitsi": "scripts/build-jitsi.sh",
+    "build:jitsi": "node scripts/build-jitsi.js",
     "build:res": "node scripts/copy-res.js",
     "build:genfiles": "yarn reskindex && yarn build:res && yarn build:jitsi",
     "build:modernizr": "modernizr -c .modernizr.json -d src/vector/modernizr.js",
@@ -135,6 +135,7 @@
     "minimist": "^1.2.0",
     "mkdirp": "^0.5.1",
     "modernizr": "^3.6.0",
+    "node-fetch": "^2.6.0",
     "optimize-css-assets-webpack-plugin": "^5.0.3",
     "postcss-extend": "^1.0.5",
     "postcss-hexrgba": "^2.0.0",
diff --git a/scripts/build-jitsi.js b/scripts/build-jitsi.js
new file mode 100644
index 00000000..56c81c16
--- /dev/null
+++ b/scripts/build-jitsi.js
@@ -0,0 +1,22 @@
+// This is a JS script so that the directory is created in-process on Windows.
+// Sorry.
+
+const fs = require("fs");
+const path = require("path");
+const mkdirp = require("mkdirp");
+const fetch = require("node-fetch");
+
+console.log("Making webapp directory");
+mkdirp.sync("webapp");
+
+// curl -s https://jitsi.riot.im/libs/external_api.min.js > ./webapp/jitsi_external_api.min.js
+console.log("Downloading Jitsi script");
+const fname = path.join("webapp", "jitsi_external_api.min.js");
+fetch("https://jitsi.riot.im/libs/external_api.min.js").then(res => {
+   const stream = fs.createWriteStream(fname);
+   return new Promise((resolve, reject) => {
+       res.body.pipe(stream);
+       res.body.on('error', err => reject(err));
+       res.body.on('finish', () => resolve());
+   });
+}).then(() => console.log('Done with Jitsi download'));
diff --git a/scripts/build-jitsi.sh b/scripts/build-jitsi.sh
deleted file mode 100755
index 5d4bdafe..00000000
--- a/scripts/build-jitsi.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/bin/bash
-
-if [[ ! -f "./webapp" ]]; then
-  mkdir "./webapp"
-fi
-
-curl -s https://jitsi.riot.im/libs/external_api.min.js > ./webapp/jitsi_external_api.min.js
diff --git a/yarn.lock b/yarn.lock
index 8a9bc0e5..273d3fd8 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -7645,8 +7645,8 @@ matrix-mock-request@^1.2.3:
     create-react-class "^15.6.0"
     diff-dom "^4.1.3"
     diff-match-patch "^1.0.4"
-    emojibase-data "^5.0.1"
-    emojibase-regex "^4.0.1"
+    emojibase-data "^4.0.2"
+    emojibase-regex "^3.0.0"
     escape-html "^1.0.3"
     file-saver "^1.3.3"
     filesize "3.5.6"
@@ -8136,6 +8136,11 @@ node-fetch@^1.0.1:
     encoding "^0.1.11"
     is-stream "^1.0.1"
 
+node-fetch@^2.6.0:
+  version "2.6.0"
+  resolved "https://registry.yarnpkg.com/node-fetch/-/node-fetch-2.6.0.tgz#e633456386d4aa55863f676a7ab0daa8fdecb0fd"
+  integrity sha512-8dG4H5ujfvFiqDmVu9fQ5bOHUC15JMjMY/Zumv26oOvvVJjM67KF8koCWIabKQ1GJIa9r2mMZscBq/TbdOcmNA==
+
 node-forge@0.9.0:
   version "0.9.0"
   resolved "https://registry.yarnpkg.com/node-forge/-/node-forge-0.9.0.tgz#d624050edbb44874adca12bb9a52ec63cb782579"
@@ -8191,22 +8196,6 @@ node-notifier@^5.4.2:
     shellwords "^0.1.1"
     which "^1.3.0"
 
-node-pre-gyp@*:
-  version "0.14.0"
-  resolved "https://registry.yarnpkg.com/node-pre-gyp/-/node-pre-gyp-0.14.0.tgz#9a0596533b877289bcad4e143982ca3d904ddc83"
-  integrity sha512-+CvDC7ZttU/sSt9rFjix/P05iS43qHCOOGzcr3Ry99bXG7VX953+vFyEuph/tfqoYu8dttBkE86JSKBO2OzcxA==
-  dependencies:
-    detect-libc "^1.0.2"
-    mkdirp "^0.5.1"
-    needle "^2.2.1"
-    nopt "^4.0.1"
-    npm-packlist "^1.1.6"
-    npmlog "^4.0.2"
-    rc "^1.2.7"
-    rimraf "^2.6.1"
-    semver "^5.3.0"
-    tar "^4.4.2"
-
 node-pre-gyp@^0.11.0:
   version "0.11.0"
   resolved "https://registry.yarnpkg.com/node-pre-gyp/-/node-pre-gyp-0.11.0.tgz#db1f33215272f692cd38f03238e3e9b47c5dd054"
@@ -11693,7 +11682,7 @@ tar-stream@^2.1.0:
     inherits "^2.0.3"
     readable-stream "^3.1.1"
 
-tar@^4, tar@^4.4.2:
+tar@^4:
   version "4.4.13"
   resolved "https://registry.yarnpkg.com/tar/-/tar-4.4.13.tgz#43b364bc52888d555298637b10d60790254ab525"
   integrity sha512-w2VwSrBoHa5BsSyH+KxEqeQBAllHhccyMFVHtGtdMpF4W7IRWfZjFiQceJPChOeTsSDVUpER2T8FA93pr0L+QA==