diff --git a/package.json b/package.json
index b9ec57d3c3..8ca79b28b6 100644
--- a/package.json
+++ b/package.json
@@ -45,9 +45,9 @@
         "build:bundle-stats": "webpack --progress --mode production --json > webpack-stats.json",
         "build:module_system": "tsc --project ./tsconfig.module_system.json && node ./lib/module_system/scripts/install.js",
         "dist": "scripts/package.sh",
-        "start": "yarn build:module_system && concurrently --kill-others-on-fail --prefix \"{time} [{name}]\" -n res,element-js \"yarn start:res\" \"yarn start:js\"",
+        "start": "concurrently --kill-others-on-fail --prefix \"{time} [{name}]\" -n modules,res,jitsi \"yarn build:module_system\" \"yarn build:res\" \"yarn build:jitsi\" && concurrently --kill-others-on-fail --prefix \"{time} [{name}]\" -n res,element-js \"yarn start:res\" \"yarn start:js\"",
         "start:https": "concurrently --kill-others-on-fail --prefix \"{time} [{name}]\" -n res,element-js \"yarn start:res\" \"yarn start:js --https\"",
-        "start:res": "yarn build:jitsi && ts-node scripts/copy-res.ts -w",
+        "start:res": "ts-node scripts/copy-res.ts -w",
         "start:js": "webpack serve --output-path webapp --mode development",
         "lint": "yarn lint:types && yarn lint:js && yarn lint:style",
         "lint:js": "yarn lint:js:src && yarn lint:js:module_system",
diff --git a/scripts/copy-res.ts b/scripts/copy-res.ts
index b31bfdb620..d4ecad8ee7 100755
--- a/scripts/copy-res.ts
+++ b/scripts/copy-res.ts
@@ -19,10 +19,7 @@ const INCLUDE_LANGS = [...new Set([...fs.readdirSync(I18N_BASE_PATH), ...fs.read
 // cpx includes globbed parts of the filename in the destination, but excludes
 // common parents. Hence, "res/{a,b}/**": the output will be "dest/a/..." and
 // "dest/b/...".
-const COPY_LIST: [
-    sourceGlob: string,
-    outputPath: string,
-][] = [
+const COPY_LIST: [sourceGlob: string, outputPath: string][] = [
     ["res/apple-app-site-association", "webapp"],
     ["res/manifest.json", "webapp"],
     ["res/sw.js", "webapp"],
@@ -65,7 +62,7 @@ function createCpx(source: string, dest: string): Cpx {
         });
     }
     return cpx;
-};
+}
 
 const logWatch = (path: string) => {
     if (verbose) {
@@ -96,8 +93,12 @@ function next(i: number, err?: Error): void {
         const copy = (path: string): void => {
             createCpx(path, dest).copy(errCheck);
         };
-        chokidar.watch(source)
-            .on("ready", () => { logWatch(source); cb(); })
+        chokidar
+            .watch(source, { ignoreInitial: true })
+            .on("ready", () => {
+                logWatch(source);
+                cb();
+            })
             .on("add", copy)
             .on("change", copy)
             .on("error", errCheck);
@@ -106,7 +107,7 @@ function next(i: number, err?: Error): void {
     }
 }
 
-function genLangFile(lang: string, dest: string): string {
+function prepareLangFile(lang: string, dest: string): [filename: string, json: string] {
     const reactSdkFile = REACT_I18N_BASE_PATH + lang + ".json";
     const riotWebFile = I18N_BASE_PATH + lang + ".json";
 
@@ -127,12 +128,14 @@ function genLangFile(lang: string, dest: string): string {
     const digest = loaderUtils.getHashDigest(jsonBuffer, null, "hex", 7);
     const filename = `${lang}.${digest}.json`;
 
+    return [filename, json];
+}
+
+function genLangFile(dest: string, filename: string, json: string) {
     fs.writeFileSync(dest + filename, json);
     if (verbose) {
         console.log("Generated language file: " + filename);
     }
-
-    return filename;
 }
 
 function genLangList(langFileMap: Record<string, string>): void {
@@ -175,15 +178,19 @@ function watchLanguage(lang: string, dest: string, langFileMap: Record<string, s
             clearTimeout(makeLangDebouncer);
         }
         makeLangDebouncer = setTimeout(() => {
-            const filename = genLangFile(lang, dest);
+            const [filename, json] = prepareLangFile(lang, dest);
+            genLangFile(dest, filename, json);
             langFileMap[lang] = filename;
             genLangList(langFileMap);
         }, 500);
     };
 
     [reactSdkFile, riotWebFile].forEach(function (f) {
-        chokidar.watch(f)
-            .on("ready", () => { logWatch(f); })
+        chokidar
+            .watch(f, { ignoreInitial: true })
+            .on("ready", () => {
+                logWatch(f);
+            })
             .on("add", makeLang)
             .on("change", makeLang)
             .on("error", errCheck);
@@ -193,14 +200,18 @@ function watchLanguage(lang: string, dest: string, langFileMap: Record<string, s
 // language resources
 const I18N_DEST = "webapp/i18n/";
 const I18N_FILENAME_MAP = INCLUDE_LANGS.reduce<Record<string, string>>((m, l) => {
-    const filename = genLangFile(l, I18N_DEST);
+    const [filename, json] = prepareLangFile(l, I18N_DEST);
+    if (!watch) {
+        genLangFile(I18N_DEST, filename, json);
+    }
     m[l] = filename;
     return m;
 }, {});
-genLangList(I18N_FILENAME_MAP);
 
 if (watch) {
     INCLUDE_LANGS.forEach((l) => watchLanguage(l, I18N_DEST, I18N_FILENAME_MAP));
+} else {
+    genLangList(I18N_FILENAME_MAP);
 }
 
 // non-language resources