diff --git a/scripts/background.js b/scripts/background.js
index 843598c..c3af5bf 100644
--- a/scripts/background.js
+++ b/scripts/background.js
@@ -1,20 +1,21 @@
 class BackgroundWorker {
-
-  constructor() {
-  }
-
   run() {
-    trektor.browser.runtime.onMessage.addListener(async (msg) => {
+    trektor.browser.runtime.onMessage.addListener((msg, _, sendResponse) => {
       switch (msg.action) {
         case "track":
-          await this.track(...msg.args);
-          return;
+          this.track(...msg.args)
+            .then(() => sendResponse())
+            .catch((e) => sendResponse(e.message));
+          break;
         case "addTask":
-          await this.addTask(...msg.args);
-          return;
+          this.addTask(...msg.args)
+            .then(() => sendResponse())
+            .catch((e) => sendResponse(e.message));
+          break;
         default:
-          throw new Error(`unknown action: ${msg.action}`);
+          new Error(`unknown action: ${msg.action}`);
       }
+      return true;
     });
   }
 
diff --git a/scripts/content_script.js b/scripts/content_script.js
index cdd789b..7d2e8aa 100644
--- a/scripts/content_script.js
+++ b/scripts/content_script.js
@@ -33,29 +33,22 @@ async function addButton() {
   trackButton.addEventListener("click", async () => {
     trackButtonIcon.classList.add("trektor-state-loading");
 
-    try {
-      await trektor.browser.runtime.sendMessage({
-        action: "track",
-        args: [window.location.pathname.split("/", 3)[2]],
-      });
-      trackButtonIcon.classList.replace("icon-clock", "icon-check-circle");
-      window.setTimeout(() => trackButtonIcon.classList.replace("icon-check-circle", "icon-clock"), 2000);
-    } catch (err) {
-      window.alert(err);
-    } finally {
-      trackButtonIcon.classList.remove("trektor-state-loading");
-    }
+    const response = await trektor.browser.runtime.sendMessage({
+      action: "track",
+      args: [window.location.pathname.split("/", 3)[2]],
+    });
+    trackButtonIcon.classList.replace("icon-clock", "icon-check-circle");
+    window.setTimeout(() => trackButtonIcon.classList.replace("icon-check-circle", "icon-clock"), 2000);
+    if (response !== null) window.alert(response);
+    trackButtonIcon.classList.remove("trektor-state-loading");
   });
 
   addButton.addEventListener("click", async () => {
-    try {
-      await trektor.browser.runtime.sendMessage({
-        action: "addTask",
-        args: [window.location.pathname.split("/", 3)[2]],
-      });
-    } catch (err) {
-      window.alert(err);
-    }
+    const response = await trektor.browser.runtime.sendMessage({
+      action: "addTask",
+      args: [window.location.pathname.split("/", 3)[2]],
+    });
+    if (response !== null) window.alert(response);
   });
 }