diff --git a/dcs/frames/__init__.py b/dcs/frames/__init__.py
index 5dc59ba..754ba8e 100644
--- a/dcs/frames/__init__.py
+++ b/dcs/frames/__init__.py
@@ -20,6 +20,7 @@
 from .ch05_qam import Ch05QamWindow
 from .ch06_filter import Ch06FilterWindow
 from .ch06_mixer import Ch06MixerWindow
+from .ch06_down_sampling import Ch06DownSamplingWindow
 
 
 def get_windows() -> List[Type[base.Window]]:
@@ -37,6 +38,7 @@
         Ch05QamWindow,
         Ch06FilterWindow,
         Ch06MixerWindow,
+        Ch06DownSamplingWindow,
     ]