diff --git a/lib/browser.ts b/lib/browser.ts
index 8295288..c9076a6 100644
--- a/lib/browser.ts
+++ b/lib/browser.ts
@@ -117,3 +117,4 @@ export const {windows} = polyfill;
 export const {theme} = polyfill;
 
 export const CHROME = navigator.appVersion.includes("Chrome/");
+export const OPERA = navigator.appVersion.includes("OPR/");
diff --git a/lib/manager/man.ts b/lib/manager/man.ts
index bfc2c37..240187f 100644
--- a/lib/manager/man.ts
+++ b/lib/manager/man.ts
@@ -16,7 +16,7 @@ import { Download } from "./download";
 import { ManagerPort } from "./port";
 import { Scheduler } from "./scheduler";
 import { Limits } from "./limits";
-import { downloads, runtime, webRequest, CHROME } from "../browser";
+import { downloads, runtime, webRequest, CHROME, OPERA } from "../browser";
 
 const US = runtime.getURL("");
 
@@ -240,7 +240,7 @@ export class Manager extends EventEmitter {
     if (this.notifiedFinished || this.running.size || this.retrying.size) {
       return;
     }
-    if (SOUNDS.value) {
+    if (SOUNDS.value && !OPERA) {
       const audio = new Audio(runtime.getURL("/style/done.opus"));
       audio.addEventListener("canplaythrough", () => audio.play());
       audio.addEventListener("ended", () => document.body.removeChild(audio));
diff --git a/util/build.py b/util/build.py
index 055d5a5..9479efc 100755
--- a/util/build.py
+++ b/util/build.py
@@ -25,6 +25,8 @@ RELEASE_ID = "{DDC359D1-844A-42a7-9AA1-88A850A938A8}"
 UNCOMPRESSABLE = set((".png", ".jpg", ".zip", ".woff2"))
 LICENSED = set((".css", ".html", ".js", "*.ts"))
 IGNORED = set((".DS_Store", "Thumbs.db"))
+# XXX: #125
+IGNORED_OPERA = set(("done.opus", "error.opus"))
 
 PERM_IGNORED_FX = set(("downloads.shelf", "webRequest", "webRequestBlocking"))
 PERM_IGNORED_CHROME = set(("menus", "sessions", "theme"))
@@ -45,17 +47,17 @@ def check_licenses():
         raise Exception(f"No license in {file}")
 
 
-def files():
+def files(additional_ignored):
   p = Path("")
   for pattern in FILES:
     for file in sorted(p.glob(pattern)):
-      if file.name in IGNORED or not file.is_file():
+      if file.name in IGNORED or file.name in additional_ignored or not file.is_file():
         continue
       yield file
 
-def build(out, manifest):
+def build(out, manifest, additional_ignored=set()):
   with ZipFile(out, "w", compression=ZIP_DEFLATED, allowZip64=False, compresslevel=2) as zp:
-    for file in files():
+    for file in files(additional_ignored):
       if str(file) == "manifest.json":
         buf = manifest
       else:
@@ -101,7 +103,7 @@ def build_firefox(args):
   build(out, json.dumps(infos, indent=2).encode("utf-8"))
 
   
-def build_chrome(args):
+def build_chromium(args, pkg, additional_ignored=set()):
   now = datetime.now().strftime("%Y%m%d%H%M%S")
   with open("manifest.json") as manip:
     infos = json.load(manip, object_pairs_hook=OrderedDict)
@@ -117,15 +119,15 @@ def build_chrome(args):
     infos["version_name"] = f"{version}-{args.mode}"
     infos["short_name"] = infos.get("name")
     infos["name"] = f"{infos.get('name')} {args.mode}"
-  
+
   infos["permissions"] = [p for p in infos.get("permissions") if not p in PERM_IGNORED_CHROME]
-  out = Path("web-ext-artifacts") / f"dta-{version}-{args.mode}-crx.zip"
+  out = Path("web-ext-artifacts") / f"dta-{version}-{args.mode}-{pkg}.zip"
   if not out.parent.exists():
     out.parent.mkdir()
   if out.exists():
     out.unlink()
   print("Output", out)
-  build(out, json.dumps(infos, indent=2).encode("utf-8"))
+  build(out, json.dumps(infos, indent=2).encode("utf-8"), additional_ignored=additional_ignored)
 
 def main():
   from argparse import ArgumentParser
@@ -140,7 +142,8 @@ def main():
     else:
       run([script], shell=True)
   build_firefox(args)
-  build_chrome(args)
+  build_chromium(args, "crx")
+  build_chromium(args, "opr", IGNORED_OPERA)
   print("DONE.")
 
 if __name__ == "__main__":
diff --git a/windows/prefs.ts b/windows/prefs.ts
index 1749183..5b58970 100644
--- a/windows/prefs.ts
+++ b/windows/prefs.ts
@@ -19,7 +19,7 @@ import { iconForPath, visible } from "../lib/windowutils";
 import { VirtualTable } from "../uikit/lib/table";
 import { Icons } from "./icons";
 import { $ } from "./winutil";
-import { runtime, storage } from "../lib/browser";
+import { runtime, storage, OPERA } from "../lib/browser";
 import "./theme";
 
 const ICON_BASE_SIZE = 16;
@@ -558,7 +558,14 @@ addEventListener("DOMContentLoaded", async () => {
   new BoolPref("pref-manager-in-popup", "manager-in-popup");
   new BoolPref("pref-queue-notification", "queue-notification");
   new BoolPref("pref-finish-notification", "finish-notification");
-  new BoolPref("pref-sounds", "sounds");
+  // XXX: #125
+  const sounds = new BoolPref("pref-sounds", "sounds");
+  if (OPERA) {
+    const sp = sounds.elem.parentElement;
+    if (sp) {
+      sp.style.display = "none";
+    }
+  }
   new BoolPref("pref-hide-context", "hide-context");
   new BoolPref("pref-tooltip", "tooltip");
   new BoolPref("pref-open-manager-on-queue", "open-manager-on-queue");