diff --git a/addons/hw_drivers/controllers/driver.py b/addons/hw_drivers/controllers/driver.py
index 6ef1bb56e94..7cda51f9f9d 100755
--- a/addons/hw_drivers/controllers/driver.py
+++ b/addons/hw_drivers/controllers/driver.py
@@ -475,7 +475,7 @@ if terminal_id:
     mpdm.start()
 else:
     try:
-        subprocess.check_call(["pkill", "9", "eftdvs"])  # Check if MPD server is running
+        subprocess.check_call(["pkill", "-9", "eftdvs"])  # Check if MPD server is running
     except subprocess.CalledProcessError:
         pass