diff --git a/kwant/builder.py b/kwant/builder.py
index 79934b76a841ed2a30909bab1ebef0d1540d338c..49407e07bd5aec9a0a87dffccf30cc92c8d3ea68 100644
--- a/kwant/builder.py
+++ b/kwant/builder.py
@@ -1606,9 +1606,9 @@ class Builder:
 
         Returns
         -------
-        finalized_system : `kwant.system.FiniteSystem`
+        finalized_system : `kwant.builder.FiniteSystem`
             If there is no symmetry.
-        finalized_system : `kwant.system.InfiniteSystem`
+        finalized_system : `kwant.builder.InfiniteSystem`
             If a symmetry is present.
 
         Notes