diff --git a/concrete-optimizer-cpp/src/concrete-optimizer.rs b/concrete-optimizer-cpp/src/concrete-optimizer.rs
index 477dcefd0..e89bd8714 100644
--- a/concrete-optimizer-cpp/src/concrete-optimizer.rs
+++ b/concrete-optimizer-cpp/src/concrete-optimizer.rs
@@ -247,7 +247,7 @@ impl OperationDag {
 
 pub struct Weights(operator::Weights);
 
-fn vector(weights: &[u64]) -> Box<Weights> {
+fn vector(weights: &[i64]) -> Box<Weights> {
     Box::new(Weights(operator::Weights::vector(weights)))
 }
 
@@ -320,7 +320,7 @@ mod ffi {
         type Weights;
 
         #[namespace = "concrete_optimizer::weights"]
-        fn vector(weights: &[u64]) -> Box<Weights>;
+        fn vector(weights: &[i64]) -> Box<Weights>;
     }
 
     #[derive(Clone, Copy)]
diff --git a/concrete-optimizer-cpp/src/cpp/concrete-optimizer.cpp b/concrete-optimizer-cpp/src/cpp/concrete-optimizer.cpp
index 67987f2c6..ce19f8e44 100644
--- a/concrete-optimizer-cpp/src/cpp/concrete-optimizer.cpp
+++ b/concrete-optimizer-cpp/src/cpp/concrete-optimizer.cpp
@@ -1099,7 +1099,7 @@ void concrete_optimizer$cxxbridge1$OperationDag$dump(const ::concrete_optimizer:
 
 namespace weights {
 extern "C" {
-::concrete_optimizer::Weights *concrete_optimizer$weights$cxxbridge1$vector(::rust::Slice<const ::std::uint64_t> weights) noexcept;
+::concrete_optimizer::Weights *concrete_optimizer$weights$cxxbridge1$vector(::rust::Slice<const ::std::int64_t> weights) noexcept;
 } // extern "C"
 } // namespace weights
 
@@ -1172,7 +1172,7 @@ namespace dag {
 }
 
 namespace weights {
-::rust::Box<::concrete_optimizer::Weights> vector(::rust::Slice<const ::std::uint64_t> weights) noexcept {
+::rust::Box<::concrete_optimizer::Weights> vector(::rust::Slice<const ::std::int64_t> weights) noexcept {
   return ::rust::Box<::concrete_optimizer::Weights>::from_raw(concrete_optimizer$weights$cxxbridge1$vector(weights));
 }
 } // namespace weights
diff --git a/concrete-optimizer-cpp/src/cpp/concrete-optimizer.hpp b/concrete-optimizer-cpp/src/cpp/concrete-optimizer.hpp
index 1d83a26fa..8a77ca946 100644
--- a/concrete-optimizer-cpp/src/cpp/concrete-optimizer.hpp
+++ b/concrete-optimizer-cpp/src/cpp/concrete-optimizer.hpp
@@ -1050,6 +1050,6 @@ namespace dag {
 } // namespace dag
 
 namespace weights {
-::rust::Box<::concrete_optimizer::Weights> vector(::rust::Slice<const ::std::uint64_t> weights) noexcept;
+::rust::Box<::concrete_optimizer::Weights> vector(::rust::Slice<const ::std::int64_t> weights) noexcept;
 } // namespace weights
 } // namespace concrete_optimizer
diff --git a/concrete-optimizer-cpp/tests/src/main.cpp b/concrete-optimizer-cpp/tests/src/main.cpp
index d5b5eae84..7cda066bc 100644
--- a/concrete-optimizer-cpp/tests/src/main.cpp
+++ b/concrete-optimizer-cpp/tests/src/main.cpp
@@ -42,7 +42,7 @@ void test_dag_no_lut() {
 
   std::vector<concrete_optimizer::dag::OperatorIndex> inputs = {node1};
 
-  std::vector<uint64_t> weight_vec = {1, 1, 1};
+  std::vector<int64_t> weight_vec = {1, 1, 1};
 
   rust::cxxbridge1::Box<concrete_optimizer::Weights> weights =
       concrete_optimizer::weights::vector(slice(weight_vec));
diff --git a/concrete-optimizer/src/dag/operator/dot_kind.rs b/concrete-optimizer/src/dag/operator/dot_kind.rs
index 1dc47ac6a..55eb89232 100644
--- a/concrete-optimizer/src/dag/operator/dot_kind.rs
+++ b/concrete-optimizer/src/dag/operator/dot_kind.rs
@@ -13,7 +13,7 @@ pub enum DotKind {
     Unsupported,
 }
 
-pub fn dot_kind(nb_inputs: u64, input_shape: &Shape, weights: &ClearTensor) -> DotKind {
+pub fn dot_kind<W>(nb_inputs: u64, input_shape: &Shape, weights: &ClearTensor<W>) -> DotKind {
     let inputs_shape = Shape::duplicated(nb_inputs, input_shape);
     if input_shape.is_number() && inputs_shape == weights.shape {
         DotKind::Simple
diff --git a/concrete-optimizer/src/dag/operator/operator.rs b/concrete-optimizer/src/dag/operator/operator.rs
index 72014d63d..d08cdefab 100644
--- a/concrete-optimizer/src/dag/operator/operator.rs
+++ b/concrete-optimizer/src/dag/operator/operator.rs
@@ -1,7 +1,7 @@
 use crate::dag::operator::tensor::{ClearTensor, Shape};
 use derive_more::{Add, AddAssign};
 
-pub type Weights = ClearTensor;
+pub type Weights = ClearTensor<i64>;
 
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub struct FunctionTable {
diff --git a/concrete-optimizer/src/dag/operator/tensor.rs b/concrete-optimizer/src/dag/operator/tensor.rs
index 477b9e13e..a09533106 100644
--- a/concrete-optimizer/src/dag/operator/tensor.rs
+++ b/concrete-optimizer/src/dag/operator/tensor.rs
@@ -1,3 +1,5 @@
+use std::{iter::Sum, ops::Mul};
+
 use delegate::delegate;
 
 use crate::utils::square_ref;
@@ -59,20 +61,23 @@ impl Shape {
 }
 
 #[derive(Clone, PartialEq, Eq, Debug)]
-pub struct ClearTensor {
+pub struct ClearTensor<W> {
     pub shape: Shape,
-    pub values: Vec<u64>,
+    pub values: Vec<W>,
 }
 
-impl ClearTensor {
-    pub fn number(value: u64) -> Self {
+impl<W> ClearTensor<W>
+where
+    W: Copy + Mul<Output = W> + Sum<W>,
+{
+    pub fn number(value: W) -> Self {
         Self {
             shape: Shape::number(),
             values: vec![value],
         }
     }
 
-    pub fn vector(values: impl Into<Vec<u64>>) -> Self {
+    pub fn vector(values: impl Into<Vec<W>>) -> Self {
         let values = values.into();
         Self {
             shape: Shape::vector(values.len() as u64),
@@ -89,7 +94,7 @@ impl ClearTensor {
         }
     }
 
-    pub fn square_norm2(&self) -> u64 {
+    pub fn square_norm2(&self) -> W {
         self.values.iter().map(square_ref).sum()
     }
 }
@@ -102,15 +107,21 @@ impl From<&Self> for Shape {
 }
 
 // helps using shared weights
-impl From<&Self> for ClearTensor {
+impl<W> From<&Self> for ClearTensor<W>
+where
+    W: Copy + Mul<Output = W> + Sum<W>,
+{
     fn from(item: &Self) -> Self {
         item.clone()
     }
 }
 
 // helps using array as weights
-impl<const N: usize> From<[u64; N]> for ClearTensor {
-    fn from(item: [u64; N]) -> Self {
-        Self::vector(item)
+impl<const N: usize, W> From<[W; N]> for ClearTensor<W>
+where
+    W: Copy + Mul<Output = W> + Sum<W>,
+{
+    fn from(items: [W; N]) -> Self {
+        Self::vector(items)
     }
 }
diff --git a/concrete-optimizer/src/optimization/dag/solo_key/optimize.rs b/concrete-optimizer/src/optimization/dag/solo_key/optimize.rs
index ad38e61e0..bdf63f1a9 100644
--- a/concrete-optimizer/src/optimization/dag/solo_key/optimize.rs
+++ b/concrete-optimizer/src/optimization/dag/solo_key/optimize.rs
@@ -361,9 +361,10 @@ mod tests {
     use crate::computing_cost::cpu::CpuComplexity;
     use crate::dag::operator::{FunctionTable, Shape, Weights};
     use crate::noise_estimator::p_error::repeat_p_error;
+    use crate::optimization::atomic_pattern;
     use crate::optimization::config::SearchSpace;
     use crate::optimization::dag::solo_key::symbolic_variance::VarianceOrigin;
-    use crate::optimization::{atomic_pattern, decomposition};
+    use crate::optimization::decomposition;
     use crate::utils::square;
 
     fn small_relative_diff(v1: f64, v2: f64) -> bool {
@@ -497,7 +498,7 @@ mod tests {
         }
     }
 
-    fn v0_parameter_ref_with_dot(precision: Precision, weight: u64) {
+    fn v0_parameter_ref_with_dot(precision: Precision, weight: i64) {
         let security_level = 128;
 
         let cache = decomposition::cache(security_level);
@@ -596,7 +597,7 @@ mod tests {
 
     fn lut_with_input_base_noise_better_than_lut_with_lut_base_noise(
         precision: Precision,
-        weight: u64,
+        weight: i64,
         cache: &PersistDecompCache,
     ) {
         let weight = &Weights::number(weight);
@@ -673,7 +674,7 @@ mod tests {
         }
     }
 
-    fn circuit(dag: &mut unparametrized::OperationDag, precision: Precision, weight: u64) {
+    fn circuit(dag: &mut unparametrized::OperationDag, precision: Precision, weight: i64) {
         let input = dag.add_input(precision, Shape::number());
         let dot1 = dag.add_dot([input], [weight]);
         let lut1 = dag.add_lut(dot1, FunctionTable::UNKWOWN, precision);
@@ -682,7 +683,7 @@ mod tests {
     }
 
     fn assert_multi_precision_dominate_single(
-        weight: u64,
+        weight: i64,
         cache: &PersistDecompCache,
     ) -> Option<bool> {
         let low_precision = 4u8;
@@ -767,7 +768,7 @@ mod tests {
 
     fn check_global_p_error_input(
         dim: u64,
-        weight: u64,
+        weight: i64,
         precision: u8,
         cache: &PersistDecompCache,
     ) -> f64 {
@@ -797,7 +798,7 @@ mod tests {
 
     fn check_global_p_error_lut(
         depth: u64,
-        weight: u64,
+        weight: i64,
         precision: u8,
         cache: &PersistDecompCache,
     ) {
@@ -825,8 +826,8 @@ mod tests {
         depth: u64,
         precision_low: Precision,
         precision_high: Precision,
-        weight_low: u64,
-        weight_high: u64,
+        weight_low: i64,
+        weight_high: i64,
     ) -> unparametrized::OperationDag {
         let shape = Shape::number();
         let mut dag = unparametrized::OperationDag::new();
diff --git a/concrete-optimizer/src/optimization/dag/solo_key/symbolic_variance.rs b/concrete-optimizer/src/optimization/dag/solo_key/symbolic_variance.rs
index b0dea5545..1f5a83a85 100644
--- a/concrete-optimizer/src/optimization/dag/solo_key/symbolic_variance.rs
+++ b/concrete-optimizer/src/optimization/dag/solo_key/symbolic_variance.rs
@@ -48,6 +48,13 @@ impl std::ops::Mul<u64> for SymbolicVariance {
     }
 }
 
+impl std::ops::Mul<i64> for SymbolicVariance {
+    type Output = Self;
+    fn mul(self, sq_weight: i64) -> Self {
+        self * sq_weight as f64
+    }
+}
+
 impl SymbolicVariance {
     pub const ZERO: Self = Self {
         input_coeff: 0.0,