diff --git a/src/aare/gui/threads/prediction_subscriber.py b/src/aare/gui/threads/prediction_subscriber.py
index b5234948..42032d82 100644
--- a/src/aare/gui/threads/prediction_subscriber.py
+++ b/src/aare/gui/threads/prediction_subscriber.py
@@ -30,6 +30,14 @@ class PredictionSubscriber(QThread):
         self._sock = self._ctx.socket(zmq.SUB)
         self._sock.setsockopt(zmq.RCVTIMEO, 500)
         self._sock.setsockopt(zmq.LINGER, 0)
+        # Cap the backlog the socket may hold. Both must be set before connect()
+        # to take effect on the pipe. Defaults let the SUB queue grow to 1000
+        # messages (20 s of video at 50 Hz) with megabytes more hidden in the
+        # kernel buffer, which is the backlog _recv_latest would then have to
+        # throw away every frame. RCVBUF stays well above the ~2.5 MB/s the
+        # stream actually needs, so it costs no throughput.
+        self._sock.setsockopt(zmq.RCVHWM, 4)
+        self._sock.setsockopt(zmq.RCVBUF, 512 * 1024)
 
         self._emit_images = True
         self.running = True