diff --git a/checkbox-support/checkbox_support/scripts/run_watcher.py b/checkbox-support/checkbox_support/scripts/run_watcher.py
index ddf915dbd8..b88c2ae76f 100644
--- a/checkbox-support/checkbox_support/scripts/run_watcher.py
+++ b/checkbox-support/checkbox_support/scripts/run_watcher.py
@@ -78,10 +78,10 @@ def run(self):
         p = select.poll()
         p.register(j, j.get_events())
         if self.zapper_usb_address:
-            zapper_host = os.environ.get("ZAPPER_ADDRESS")
+            zapper_host = os.environ.get("ZAPPER_HOST")
             if not zapper_host:
                 raise SystemExit(
-                    "ZAPPER_ADDRESS environment variable not found!"
+                    "ZAPPER_HOST environment variable not found!"
                 )
             usb_address = self.zapper_usb_address
             if self.testcase == "insertion":