diff --git a/chameleond/drivers/fpga_tio.py b/chameleond/drivers/fpga_tio.py
index 4a28d33..1dc56bf 100644
--- a/chameleond/drivers/fpga_tio.py
+++ b/chameleond/drivers/fpga_tio.py
@@ -326,6 +326,7 @@
       True if the video input becomes stable within the timeout period;
       otherwise, False.
     """
+    self._SelectInput(port_id)
     return self._flows[port_id].WaitVideoInputStable(timeout)
 
   def _ReadDefaultEdid(self):