diff --git a/hacking/nix/scope/world/instances/test-automation-scripts/serial-device.py b/hacking/nix/scope/world/instances/test-automation-scripts/serial-device.py
index f27a7ee9a..370be10a6 100644
--- a/hacking/nix/scope/world/instances/test-automation-scripts/serial-device.py
+++ b/hacking/nix/scope/world/instances/test-automation-scripts/serial-device.py
@@ -18,10 +18,10 @@ def main():
 def run(args):
     child = pexpect.spawn(args.simulate, encoding='utf-8')
     child.logfile = sys.stdout
-    child.expect('echo> ', timeout=10)
-    time.sleep(5)
-    child.sendline('xxx')
-    child.expect('[x][x][x]', timeout=10)
+    child.expect('echo> ', timeout=5)
+    time.sleep(1)
+    child.send('xxx')
+    child.expect('\[x\]\[x\]\[x\]', timeout=5)
     print()
 
 if __name__ == '__main__':