diff --git a/src/main.ml b/src/main.ml
index 3a442ce..b7e26b6 100644
--- a/src/main.ml
+++ b/src/main.ml
@@ -25,7 +25,7 @@ let exec_passes ast verbose debug passes f =
 
 let _ =
   (** Usage and argument parsing. *)
-  let default_passes = ["pre2vars"] in
+  let default_passes = ["chkvar_init_unicity"; "pre2vars"] in
   let usage_msg =
     "Usage: main [-passes p1,...,pn] [-ast] [-verbose] [-debug] \
       [-o output_file] source_file\n" in
@@ -56,6 +56,7 @@ let _ =
   List.iter (fun (s, k) -> Hashtbl.add passes_table s k)
     [
       ("pre2vars", Passes.pre2vars);
+      ("chkvar_init_unicity", Passes.chkvar_init_unicity);
     ];
 
   (** Main functionality below *)
diff --git a/src/passes.ml b/src/passes.ml
index 0bbb5e1..a7977c3 100644
--- a/src/passes.ml
+++ b/src/passes.ml
@@ -115,3 +115,62 @@ let pre2vars =
   in
   expression_pass (Utils.somify aux)
 
+let chkvar_init_unicity : t_nodelist -> t_nodelist option =
+  let aux (node: t_node) : t_node option =
+    let h = Hashtbl.create Config.maxvar in
+    let add_var v =
+      match v with
+      | IVar s -> Hashtbl.add h s v
+      | BVar s -> Hashtbl.add h s v
+      | RVar s -> Hashtbl.add h s v
+    in
+    List.iter add_var (snd node.n_inputs);
+    List.iter add_var (snd node.n_outputs);
+    List.iter add_var (snd node.n_local_vars);
+    (** Remove the variables initialized in usual equations *)
+    let check_equations eqs =
+      List.fold_right
+        (fun (((_, patt), _): t_equation) (acc: bool) ->
+          if acc = false
+            then false
+            else
+              begin
+              (* assert(acc = true) *)
+              List.fold_right
+                (fun var acc ->
+                  if acc = false
+                    then false
+                    else
+                      begin
+                        let n = Utils.name_of_var var in
+                        match Hashtbl.find_opt h n with
+                        | None -> false
+                        | Some _ -> (Hashtbl.remove h n; true)
+                      end)
+                patt true
+              end)
+        node.n_equations true
+      in
+    if check_equations node.n_equations
+      then
+        begin
+          (** Remove the variables initialized in automata *)
+          if
+            List.fold_right
+              (fun (automata: t_automaton) acc ->
+                if acc = false
+                  then false
+                  else
+                    begin
+                      List.fold_right
+                        (fun (State(_, eqs, _, _): t_state) acc -> acc && check_equations eqs)
+                        (snd automata) true
+                    end)
+              node.n_automata true
+            then Some node
+            else None
+        end
+      else None
+  in
+  node_pass aux
+
diff --git a/src/utils.ml b/src/utils.ml
index 0029c14..f019946 100644
--- a/src/utils.ml
+++ b/src/utils.ml
@@ -34,3 +34,8 @@ let type_exp : t_expression -> full_ty = function
   | EApp   (full_ty , _ , _) -> full_ty
 
 let somify f = fun e -> Some (f e)
+
+let name_of_var: t_var -> ident = function
+  | IVar s -> s
+  | BVar s -> s
+  | RVar s -> s