diff --git a/assets/parser.d.erb b/assets/parser.d.erb
index 487cd58..9381d1c 100644
--- a/assets/parser.d.erb
+++ b/assets/parser.d.erb
@@ -22,7 +22,6 @@ class <%= @classname %>
 <%   end %>
 <% end %>
         _TOKEN_COUNT = <%= @grammar.tokens.size %>,
-        _TOKEN_DECODE_ERROR = <%= TOKEN_DECODE_ERROR %>,
     }
 
     struct Token
@@ -407,7 +406,6 @@ class <%= @classname %>
                 if (decoded.is_decode_error())
                 {
                     result.type = Result.Type.DECODE_ERROR;
-                    result.token = _TOKEN_DECODE_ERROR;
                     return;
                 }
                 bool lex_continue = false;
diff --git a/lib/propane.rb b/lib/propane.rb
index 01e55af..a5e7324 100644
--- a/lib/propane.rb
+++ b/lib/propane.rb
@@ -25,9 +25,6 @@ require_relative "propane/version"
 
 class Propane
 
-  # Decoding error.
-  TOKEN_DECODE_ERROR = 0xFFFFFFFD
-
   class Error < RuntimeError
   end