diff --git a/compiler/concrete-optimizer b/compiler/concrete-optimizer
index 3b9535ac2..1f15162b3 160000
--- a/compiler/concrete-optimizer
+++ b/compiler/concrete-optimizer
@@ -1 +1 @@
-Subproject commit 3b9535ac2fe1f2abe680bac647345664c2110936
+Subproject commit 1f15162b39103f5a3bf08dff4e4c4a3ac410b755
diff --git a/compiler/lib/Dialect/FHE/Analysis/ConcreteOptimizer.cpp b/compiler/lib/Dialect/FHE/Analysis/ConcreteOptimizer.cpp
index 96b3ba6c3..603c717eb 100644
--- a/compiler/lib/Dialect/FHE/Analysis/ConcreteOptimizer.cpp
+++ b/compiler/lib/Dialect/FHE/Analysis/ConcreteOptimizer.cpp
@@ -154,7 +154,7 @@ struct FunctionToDag {
   }
 
   void addDot(optimizer::Dag &dag, mlir::Value &val, Inputs &encrypted_inputs,
-              std::vector<std::uint64_t> &weights_vector) {
+              std::vector<std::int64_t> &weights_vector) {
     assert(encrypted_inputs.size() == 1);
     auto weights = concrete_optimizer::weights::vector(slice(weights_vector));
     index[val] = dag->add_dot(slice(encrypted_inputs), std::move(weights));
@@ -228,19 +228,19 @@ struct FunctionToDag {
     return value.isa<mlir::BlockArgument>();
   }
 
-  std::vector<std::uint64_t>
+  std::vector<std::int64_t>
   resolveConstantVectorWeights(mlir::arith::ConstantOp &cstOp) {
-    std::vector<std::uint64_t> values;
+    std::vector<std::int64_t> values;
     mlir::DenseIntElementsAttr denseVals =
         cstOp->getAttrOfType<mlir::DenseIntElementsAttr>("value");
 
     for (llvm::APInt val : denseVals.getValues<llvm::APInt>()) {
-      values.push_back(val.getZExtValue());
+      values.push_back(val.getSExtValue());
     }
     return values;
   }
 
-  llvm::Optional<std::vector<std::uint64_t>>
+  llvm::Optional<std::vector<std::int64_t>>
   resolveConstantWeights(mlir::Value &value) {
     if (auto cstOp = llvm::dyn_cast_or_null<mlir::arith::ConstantOp>(
             value.getDefiningOp())) {
@@ -258,7 +258,7 @@ struct FunctionToDag {
     }
   }
 
-  llvm::Optional<std::vector<std::uint64_t>>
+  llvm::Optional<std::vector<std::int64_t>>
   dotWeights(mlir::concretelang::FHELinalg::Dot &dot) {
     if (dot.getOperands().size() != 2) {
       return llvm::None;
diff --git a/compiler/tests/check_tests/Dialect/FHE/optimizer_ast.mlir b/compiler/tests/check_tests/Dialect/FHE/optimizer_ast.mlir
new file mode 100644
index 000000000..e33228cd5
--- /dev/null
+++ b/compiler/tests/check_tests/Dialect/FHE/optimizer_ast.mlir
@@ -0,0 +1,10 @@
+// RUN: concretecompiler --verbose --split-input-file --action=dump-fhe  %s 2>&1| FileCheck %s
+
+func.func @main(%arg0: tensor<5x!FHE.eint<5>>) -> !FHE.eint<5> {
+  %weights = arith.constant dense<[-1, -1, -1, -1, -1]> : tensor<5xi6>
+  %tlu = arith.constant dense<[0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]> : tensor<32xi64>
+  %0 = "FHELinalg.apply_lookup_table"(%arg0, %tlu) : (tensor<5x!FHE.eint<5>>, tensor<32xi64>) -> tensor<5x!FHE.eint<5>>
+  // CHECK: Dot { [[a:.*]], weights: ClearTensor { shape: Shape { dimensions_size: [5] }, values: [-1, -1, -1, -1, -1] }, [[b:.*]]}
+  %1 = "FHELinalg.dot_eint_int"(%0, %weights) : (tensor<5x!FHE.eint<5>>, tensor<5xi6>) -> !FHE.eint<5>
+  return %1 : !FHE.eint<5>
+}