diff --git a/src/lexer.mll b/src/lexer.mll
index a2c7d7d..3a4175c 100644
--- a/src/lexer.mll
+++ b/src/lexer.mll
@@ -62,6 +62,11 @@ rule token = parse
   | '/'             { BO_div }
   | '%'             { BO_mod }
   | "->"            { BO_arrow }
+  | "--"            { read_single_line_comment lexbuf }
   | eof             { EOF }
   | _               { raise (Lexing_error (Format.sprintf "Error when seeing %s" (lexeme lexbuf)))}
 
+and read_single_line_comment = parse
+  | '\n' { token lexbuf }
+  | eof { EOF }
+  | _ { read_single_line_comment lexbuf }
diff --git a/src/parser.mly b/src/parser.mly
index e6ac41a..8dba723 100644
--- a/src/parser.mly
+++ b/src/parser.mly
@@ -187,9 +187,9 @@ node:
 
 node_content:
   IDENT LPAREN in_params RPAREN
-  RETURNS LPAREN out_params RPAREN SEMICOL
+  RETURNS LPAREN out_params RPAREN OPTIONAL_SEMICOL
   local_params
-  LET equations TEL
+  LET equations TEL OPTIONAL_SEMICOL
     { let node_name = $1 in
       let (t_in, e_in) = $3 in
       let (t_out, e_out) = $7 in
@@ -202,6 +202,11 @@ node_content:
           n_type = FTArr (t_in, t_out); } in
       Hashtbl.add defined_nodes node_name n; n };
 
+OPTIONAL_SEMICOL:
+  | /* empty */ {}
+  | SEMICOL {}
+;
+
 in_params:
   | /* empty */ { (FTList [], []) }
   | param_list  { $1 }