diff --git a/claasp/cipher_modules/models/cp/mzn_models/mzn_deterministic_truncated_xor_differential_model.py b/claasp/cipher_modules/models/cp/mzn_models/mzn_deterministic_truncated_xor_differential_model.py
index 9ced27d3..a0533f67 100644
--- a/claasp/cipher_modules/models/cp/mzn_models/mzn_deterministic_truncated_xor_differential_model.py
+++ b/claasp/cipher_modules/models/cp/mzn_models/mzn_deterministic_truncated_xor_differential_model.py
@@ -435,10 +435,10 @@ def output_inverse_constraints(self, component):
 
         return cp_declarations, cp_constraints
 
-    def propagate_deterministically(self, component, wordwise=False):
+    def propagate_deterministically(self, component, wordwise=False, inverse=False):
         if not wordwise:
             if component.type == SBOX:
-                variables, constraints, sbox_mant = component.cp_deterministic_truncated_xor_differential_trail_constraints(self.sbox_mant)
+                variables, constraints, sbox_mant = component.cp_deterministic_truncated_xor_differential_trail_constraints(self.sbox_mant, inverse)
                 self.sbox_mant = sbox_mant
             else:
                 variables, constraints = component.cp_deterministic_truncated_xor_differential_trail_constraints()
diff --git a/claasp/cipher_modules/models/cp/mzn_models/mzn_impossible_xor_differential_model.py b/claasp/cipher_modules/models/cp/mzn_models/mzn_impossible_xor_differential_model.py
index 72b76ce5..707426a3 100644
--- a/claasp/cipher_modules/models/cp/mzn_models/mzn_impossible_xor_differential_model.py
+++ b/claasp/cipher_modules/models/cp/mzn_models/mzn_impossible_xor_differential_model.py
@@ -65,7 +65,7 @@ def build_impossible_backward_model(self, backward_components, clean = True):
         constant_components, constant_ids = self.extract_constants()
         for component in backward_components:
             if check_if_implemented_component(component):
-                variables, constraints = self.propagate_deterministically(component)
+                variables, constraints = self.propagate_deterministically(component, inverse=True)
                 inverse_variables.extend(variables)
                 inverse_constraints.extend(constraints)
         
@@ -924,4 +924,4 @@ def solve(self, model_type, solver_name=None, number_of_rounds=None, initial_rou
                               'impossible_xor_differential_one_solution']:
                 return solutions[0]
             else:
-                return solutions
\ No newline at end of file
+                return solutions