diff --git a/poulpy-core/src/conversion/mod.rs b/poulpy-core/src/conversion/mod.rs
index 9771531..8be980a 100644
--- a/poulpy-core/src/conversion/mod.rs
+++ b/poulpy-core/src/conversion/mod.rs
@@ -3,3 +3,5 @@ mod glwe_to_lwe;
 mod lwe_to_glwe;
 
 pub use gglwe_to_ggsw::*;
+pub use glwe_to_lwe::*;
+pub use lwe_to_glwe::*;
diff --git a/poulpy-core/src/keyswitching/lwe_ct.rs b/poulpy-core/src/keyswitching/lwe_ct.rs
index ff9fb5f..7aa5321 100644
--- a/poulpy-core/src/keyswitching/lwe_ct.rs
+++ b/poulpy-core/src/keyswitching/lwe_ct.rs
@@ -4,7 +4,7 @@ use poulpy_hal::{
 };
 
 use crate::{
-    ScratchTakeCore,
+    LWESampleExtract, ScratchTakeCore,
     keyswitching::glwe_ct::GLWEKeyswitch,
     layouts::{
         GGLWEInfos, GLWE, GLWEAlloc, GLWELayout, LWE, LWEInfos, LWEToMut, LWEToRef, Rank, TorusPrecision,
@@ -40,7 +40,7 @@ impl<BE: Backend> LWEKeySwitch<BE> for Module<BE> where Self: LWEKeySwitch<BE> {
 
 pub trait LWEKeySwitch<BE: Backend>
 where
-    Self: GLWEKeyswitch<BE> + GLWEAlloc,
+    Self: GLWEKeyswitch<BE> + GLWEAlloc + LWESampleExtract,
 {
     fn lwe_keyswitch_tmp_bytes<R, A, K>(&self, res_infos: &R, a_infos: &A, key_infos: &K) -> usize
     where
@@ -121,6 +121,6 @@ where
         }
 
         self.glwe_keyswitch(&mut glwe_out, &glwe_in, &ksk.0, scratch_1);
-        res.sample_extract(&glwe_out);
+        self.lwe_sample_extract(res, &glwe_out);
     }
 }