diff --git a/src/calibre/gui2/main.py b/src/calibre/gui2/main.py
index a9a06db13f..6315552263 100644
--- a/src/calibre/gui2/main.py
+++ b/src/calibre/gui2/main.py
@@ -462,7 +462,7 @@ def main(args=sys.argv):
     otherinstance = False
     try:
         listener = create_listener()
-    except socket.error:  # Good si is correct (on UNIX)
+    except socket.error:  # Good singleinstance is correct (on UNIX)
         otherinstance = True
     else:
         # On windows only singleinstance can be trusted