diff --git a/zospy/zpcore.py b/zospy/zpcore.py
index af814d9..e4fc36e 100644
--- a/zospy/zpcore.py
+++ b/zospy/zpcore.py
@@ -438,7 +438,7 @@ def connect_as_extension(
         instancenumber: int
             An integer to specify the number of the instance used.
         return_primary_system: bool
-            A boolean indicating if OpticStudioSystem should be returned directly.
+            A boolean indicating if the primary  OpticStudioSystem  should be returned.
 
         Returns
         -------