diff --git a/res/sw.js b/res/sw.js
new file mode 100644
index 00000000..038b82c9
--- /dev/null
+++ b/res/sw.js
@@ -0,0 +1 @@
+self.addEventListener('fetch',() => {});
diff --git a/scripts/copy-res.js b/scripts/copy-res.js
index 00e0cb7f..b524062b 100755
--- a/scripts/copy-res.js
+++ b/scripts/copy-res.js
@@ -58,6 +58,7 @@ const INCLUDE_LANGS = [
// "dest/b/...".
const COPY_LIST = [
["res/manifest.json", "webapp"],
+ ["res/sw.js", "webapp"],
["res/welcome.html", "webapp"],
["res/welcome/**", "webapp/welcome"],
["res/themes/**", "webapp/themes"],
diff --git a/src/vector/index.html b/src/vector/index.html
index 130e3425..fc880633 100644
--- a/src/vector/index.html
+++ b/src/vector/index.html
@@ -41,6 +41,11 @@
window.vector_indexeddb_worker_script = '<%= htmlWebpackPlugin.files.chunks['indexeddb-worker'].entry %>';
+