diff --git a/backend/mpc-system/services/service-party-android/app/src/main/AndroidManifest.xml b/backend/mpc-system/services/service-party-android/app/src/main/AndroidManifest.xml
index a441ceec..9d1636dc 100644
--- a/backend/mpc-system/services/service-party-android/app/src/main/AndroidManifest.xml
+++ b/backend/mpc-system/services/service-party-android/app/src/main/AndroidManifest.xml
@@ -31,6 +31,14 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+
+        <!-- Portrait-only QR code scanner activity -->
+        <activity
+            android:name=".presentation.screens.PortraitCaptureActivity"
+            android:screenOrientation="portrait"
+            android:stateNotNeeded="true"
+            android:theme="@style/zxing_CaptureTheme"
+            android:windowSoftInputMode="stateAlwaysHidden" />
     </application>
 
 </manifest>
diff --git a/backend/mpc-system/services/service-party-android/app/src/main/java/com/durian/tssparty/presentation/screens/CoSignJoinScreen.kt b/backend/mpc-system/services/service-party-android/app/src/main/java/com/durian/tssparty/presentation/screens/CoSignJoinScreen.kt
index 889ccf73..b4dda78a 100644
--- a/backend/mpc-system/services/service-party-android/app/src/main/java/com/durian/tssparty/presentation/screens/CoSignJoinScreen.kt
+++ b/backend/mpc-system/services/service-party-android/app/src/main/java/com/durian/tssparty/presentation/screens/CoSignJoinScreen.kt
@@ -168,7 +168,8 @@ fun CoSignJoinScreen(
                     setCameraId(0)
                     setBeepEnabled(true)
                     setBarcodeImageEnabled(false)
-                    setOrientationLocked(false)
+                    setOrientationLocked(true)
+                    setCaptureActivity(PortraitCaptureActivity::class.java)
                 }
                 scanLauncher.launch(options)
             },
diff --git a/backend/mpc-system/services/service-party-android/app/src/main/java/com/durian/tssparty/presentation/screens/JoinKeygenScreen.kt b/backend/mpc-system/services/service-party-android/app/src/main/java/com/durian/tssparty/presentation/screens/JoinKeygenScreen.kt
index 75594631..1eeb9393 100644
--- a/backend/mpc-system/services/service-party-android/app/src/main/java/com/durian/tssparty/presentation/screens/JoinKeygenScreen.kt
+++ b/backend/mpc-system/services/service-party-android/app/src/main/java/com/durian/tssparty/presentation/screens/JoinKeygenScreen.kt
@@ -220,6 +220,7 @@ private fun InputScreen(
                     setBeepEnabled(true)
                     setBarcodeImageEnabled(false)
                     setOrientationLocked(true)
+                    setCaptureActivity(PortraitCaptureActivity::class.java)
                 }
                 scanLauncher.launch(options)
             },
diff --git a/backend/mpc-system/services/service-party-android/app/src/main/java/com/durian/tssparty/presentation/screens/PortraitCaptureActivity.kt b/backend/mpc-system/services/service-party-android/app/src/main/java/com/durian/tssparty/presentation/screens/PortraitCaptureActivity.kt
new file mode 100644
index 00000000..8cbf1b61
--- /dev/null
+++ b/backend/mpc-system/services/service-party-android/app/src/main/java/com/durian/tssparty/presentation/screens/PortraitCaptureActivity.kt
@@ -0,0 +1,9 @@
+package com.durian.tssparty.presentation.screens
+
+import com.journeyapps.barcodescanner.CaptureActivity
+
+/**
+ * Portrait-only barcode capture activity
+ * Used to force the QR scanner to use portrait orientation
+ */
+class PortraitCaptureActivity : CaptureActivity()