diff --git a/streaming-agent/gst_agent.py b/streaming-agent/gst_agent.py
index 1075328..c9b0627 100755
--- a/streaming-agent/gst_agent.py
+++ b/streaming-agent/gst_agent.py
@@ -145,10 +145,13 @@ class CSSStreamAgent:
             f'webrtcbin. '
 
             # Game audio: pipewiresrc → Opus
-            # pipewiresrc is the native PipeWire GStreamer source (Ubuntu 24+/26).
-            # It connects to the default audio output monitor via PipeWire directly,
-            # avoiding the PulseAudio compatibility layer entirely.
-            f'pipewiresrc ! '
+            # target-object=game_output pins capture to the game audio sink.
+            # Without this, pipewiresrc defaults to the system capture device
+            # (virtual_mic / microphone) instead of the game audio monitor.
+            # stream.capture.sink=true tells PipeWire to use game_output's
+            # monitor ports rather than treating it as a regular source node.
+            f'pipewiresrc target-object=game_output '
+            f'stream-properties="props,stream.capture.sink=(boolean)true" ! '
             f'audio/x-raw,format=F32LE,rate=48000,channels=2 ! '
             f'audioconvert ! '
             f'opusenc ! '