diff --git a/src/config.ml b/src/config.ml
index 6046dee..3255356 100644
--- a/src/config.ml
+++ b/src/config.ml
@@ -2,3 +2,4 @@
     * This corresponds to the sum of the number of local, input and output
     * variables. *)
 let maxvar = 100
+
diff --git a/src/main.ml b/src/main.ml
index c1334ea..450e81d 100644
--- a/src/main.ml
+++ b/src/main.ml
@@ -36,7 +36,6 @@ let _ =
   let nopopt = ref false in
   let simopt = ref false in
   let passes = ref [] in
-  let main_fn = ref "main" in
   let source_file = ref "" in
   let testopt = ref false in
   let output_file = ref "out.c" in
@@ -53,8 +52,6 @@ let _ =
       ("-p", Arg.String (fun s -> passes := s :: !passes),
             "Add a pass to the compilation process");
       ("-sim", Arg.Set simopt, "Simulate the main node");
-      ("-m", Arg.String (fun s -> main_fn := s),
-            "Defines what the main function is (defaults to main).");
       ("-o", Arg.Set_string output_file, "Output file (defaults to [out.c])");
     ] in
   Arg.parse speclist anon_fun usage_msg ;
@@ -62,7 +59,7 @@ let _ =
   if !passes = [] then passes := default_passes;
   let print_verbose = print_verbose !verbose in
   let print_debug = print_debug !debug in
-  let main_fn = !main_fn in
+  let main_fn = "main" in
 
   (** Definition of the passes table *)
   let passes_table  = Hashtbl.create 100 in
diff --git a/src/parser.mly b/src/parser.mly
index f8660d5..c6a1305 100644
--- a/src/parser.mly
+++ b/src/parser.mly
@@ -199,18 +199,26 @@ node_content:
           n_local_vars = $10;
           n_equations  = eqs;
           n_automata = aut; } in
-      if Hashtbl.find_opt defined_nodes node_name <> None
+      if List.length (snd $10) = 0 && node_name <> "main"
         then raise (MyParsingError
-                    (Format.asprintf "The node %s is already defined."
-                                      node_name,
+                    (Format.asprintf "The node %s should have arguments."
+                      node_name,
                     current_location()))
         else
-          if vars_distinct e_in e_out (snd $10)
-            then (Hashtbl.add defined_nodes node_name n; n)
-            else raise (MyParsingError
-                        ("There is a conflict between the names of local, input \
-                        or output variables.",
-                        current_location())) };
+          begin
+          if Hashtbl.find_opt defined_nodes node_name <> None
+            then raise (MyParsingError
+                        (Format.asprintf "The node %s is already defined."
+                                          node_name,
+                        current_location()))
+            else
+              if vars_distinct e_in e_out (snd $10)
+                then (Hashtbl.add defined_nodes node_name n; n)
+                else raise (MyParsingError
+                            ("There is a conflict between the names of local, input \
+                            or output variables.",
+                            current_location()))
+          end};
 
 node_body:
   | /* empty */ { ([], []) }