diff --git a/public/jsQrWorker.js b/public/jsQrWorker.js
index 24b6701..5bf759e 100644
--- a/public/jsQrWorker.js
+++ b/public/jsQrWorker.js
@@ -16,9 +16,20 @@ self.addEventListener('message', event => {
   const t1 = new Date().getTime();
   if (code != null) {
     console.log(`Scanned in ${t1-t0} ms`);
+    // Send data back to main JS thread if QR code was found
     postMessage({
       data: code.data,
       ms: t1-t0
     });
   }
-});
\ No newline at end of file
+  else {
+    if (event.data.alwaysRespond) {
+      // If alwaysRespond is true, send back empty result when scanning finished
+      postMessage({
+        data: undefined,
+        type: undefined,
+        ms: t1-t0
+      });
+    }
+  }
+});
diff --git a/public/wasmWorker.js b/public/wasmWorker.js
index f7d0116..27af639 100644
--- a/public/wasmWorker.js
+++ b/public/wasmWorker.js
@@ -20,11 +20,22 @@ importScripts("wasm/koder.js");
     const scanResult = koder.decode(data, this.width, this.height);
     const t1 = new Date().getTime();
     if (scanResult) {
+      // Send data back to main JS thread if QR code was found
       postMessage({
         data: scanResult.code,
         type: scanResult.type,
         ms: t1-t0
       });
     }
+    else {
+      if (event.data.alwaysRespond) {
+        // If alwaysRespond is true, send back empty result when scanning finished
+        postMessage({
+          data: undefined,
+          type: undefined,
+          ms: t1-t0
+        });
+      }
+    }
   });
-})();
\ No newline at end of file
+})();