diff --git a/scripts/uart-console.py b/scripts/uart-console.py
index 8a46e8d..69db5c8 100755
--- a/scripts/uart-console.py
+++ b/scripts/uart-console.py
@@ -10,14 +10,16 @@ The bring-up diagnostics (w5100_selftest / w5100_udptest / w5100_regdump) just
 stream a status line on the same port, so this works for those too.
 
 Usage:
-    sudo ./scripts/uart-console.py                 # /dev/ttyUSB1 @ 115200
+    sudo /opt/venv/bin/python3 scripts/uart-console.py   # /dev/ttyUSB1 @ 115200
     sudo ./scripts/uart-console.py /dev/ttyUSB0 115200
     ./scripts/uart-console.py --send "udp broadcast hi"   # one-shot, no tty
     ./scripts/uart-console.py --read 5                    # just dump 5s of output
 
 Channel A of the FT2232H is the MPSSE/iceprog port; the UART is channel B, which
 is normally the SECOND ttyUSB (…USB1).  Needs read/write on the device node —
-run under sudo, or add yourself to the port's group.
+run under sudo, or add yourself to the port's group.  In the devcontainer
+pyserial lives in /opt/venv, which plain `sudo python3` does NOT see — invoke
+`sudo /opt/venv/bin/python3` explicitly or you just get "needs pyserial".
 
 Quit the interactive console with Ctrl-] (or Ctrl-C).
 """