diff --git a/.github/workflows/codespell.yaml b/.github/workflows/codespell.yaml
index 7632ba8e..fae65a6c 100644
--- a/.github/workflows/codespell.yaml
+++ b/.github/workflows/codespell.yaml
@@ -13,4 +13,3 @@ jobs:
           check_filenames: true
           check_hidden: true
           ignore_words_file: .codespellignore
-          exclude_file: lib/lrama/new_parser.rb
diff --git a/Rakefile b/Rakefile
index 6a8ac011..077bf110 100644
--- a/Rakefile
+++ b/Rakefile
@@ -3,11 +3,11 @@ require "bundler/gem_tasks"
 namespace "build" do
   desc "build parser from parser.y by using Racc"
   task :racc_parser do
-    `bundle exec racc parser.y --embedded -o lib/lrama/new_parser.rb`
+    `bundle exec racc parser.y --embedded -o lib/lrama/parser.rb`
   end
 
   desc "build parser for debugging"
   task :racc_verbose_parser do
-    `bundle exec racc parser.y --embedded -o lib/lrama/new_parser.rb -t --log-file=parser.output`
+    `bundle exec racc parser.y --embedded -o lib/lrama/parser.rb -t --log-file=parser.output`
   end
 end
diff --git a/lib/lrama.rb b/lib/lrama.rb
index aa813a52..f9c5ec16 100644
--- a/lib/lrama.rb
+++ b/lib/lrama.rb
@@ -8,7 +8,7 @@
 require "lrama/option_parser"
 require "lrama/options"
 require "lrama/output"
-# require "lrama/parser"
+require "lrama/parser"
 require "lrama/report"
 require "lrama/state"
 require "lrama/states"
@@ -16,5 +16,4 @@
 require "lrama/type"
 require "lrama/version"
 require "lrama/warning"
-require "lrama/new_parser"
 require "lrama/new_lexer"
diff --git a/lib/lrama/command.rb b/lib/lrama/command.rb
index 213b7acb..5d8957da 100644
--- a/lib/lrama/command.rb
+++ b/lib/lrama/command.rb
@@ -8,7 +8,7 @@ def run(argv)
       warning = Lrama::Warning.new
       text = options.y.read
       options.y.close if options.y != STDIN
-      grammar = Lrama::NewParser.new(text).parse
+      grammar = Lrama::Parser.new(text).parse
       states = Lrama::States.new(grammar, warning, trace_state: (options.trace_opts[:automaton] || options.trace_opts[:closure]))
       states.compute
       context = Lrama::Context.new(states)
diff --git a/lib/lrama/new_parser.rb b/lib/lrama/parser.rb
similarity index 99%
rename from lib/lrama/new_parser.rb
rename to lib/lrama/parser.rb
index dc0c77f7..efa87da8 100644
--- a/lib/lrama/new_parser.rb
+++ b/lib/lrama/parser.rb
@@ -666,7 +666,7 @@ def token_to_str(t)
 end
 ###### racc/parser.rb end
 module Lrama
-  class NewParser < Racc::Parser
+  class Parser < Racc::Parser
 
 module_eval(<<'...end parser.y/module_eval...', 'parser.y', 388)
 
@@ -1787,5 +1787,5 @@ def _reduce_none(val, _values, result)
   val[0]
 end
 
-  end   # class NewParser
+  end   # class Parser
 end   # module Lrama
diff --git a/parser.y b/parser.y
index 27b1566f..126da691 100644
--- a/parser.y
+++ b/parser.y
@@ -1,4 +1,4 @@
-class Lrama::NewParser
+class Lrama::Parser
 rule
   input: prologue_declarations bison_declarations "%%" grammar epilogue_opt
 
diff --git a/spec/lrama/context_spec.rb b/spec/lrama/context_spec.rb
index d81d5964..a8ff640d 100644
--- a/spec/lrama/context_spec.rb
+++ b/spec/lrama/context_spec.rb
@@ -5,7 +5,7 @@
   describe "basic" do
     it do
       y = File.read(fixture_path("context/basic.y"))
-      grammar = Lrama::NewParser.new(y).parse
+      grammar = Lrama::Parser.new(y).parse
       states = Lrama::States.new(grammar, warning)
       states.compute
       context = Lrama::Context.new(states)
@@ -181,7 +181,7 @@
 %%
         INPUT
 
-        grammar = Lrama::NewParser.new(y).parse
+        grammar = Lrama::Parser.new(y).parse
         states = Lrama::States.new(grammar, warning)
         states.compute
         context = Lrama::Context.new(states)
@@ -230,7 +230,7 @@
 %%
         INPUT
 
-        grammar = Lrama::NewParser.new(y).parse
+        grammar = Lrama::Parser.new(y).parse
         states = Lrama::States.new(grammar, warning)
         states.compute
         context = Lrama::Context.new(states)
diff --git a/spec/lrama/counterexamples_spec.rb b/spec/lrama/counterexamples_spec.rb
index 501d680d..f0cce980 100644
--- a/spec/lrama/counterexamples_spec.rb
+++ b/spec/lrama/counterexamples_spec.rb
@@ -50,7 +50,7 @@
       end
 
       it "build counterexamples of S/R conflicts" do
-        grammar = Lrama::NewParser.new(y).parse
+        grammar = Lrama::Parser.new(y).parse
         states = Lrama::States.new(grammar, warning)
         states.compute
         counterexamples = Lrama::Counterexamples.new(states)
@@ -249,7 +249,7 @@
       end
 
       it "build counterexamples of R/R conflicts" do
-        grammar = Lrama::NewParser.new(y).parse
+        grammar = Lrama::Parser.new(y).parse
         states = Lrama::States.new(grammar, warning)
         states.compute
         counterexamples = Lrama::Counterexamples.new(states)
@@ -326,7 +326,7 @@
       end
 
       it "build counterexamples of S/R conflicts" do
-        grammar = Lrama::NewParser.new(y).parse
+        grammar = Lrama::Parser.new(y).parse
         states = Lrama::States.new(grammar, warning)
         states.compute
         counterexamples = Lrama::Counterexamples.new(states)
@@ -407,7 +407,7 @@
       end
 
       it "build counterexamples of S/R and R/R conflicts" do
-        grammar = Lrama::NewParser.new(y).parse
+        grammar = Lrama::Parser.new(y).parse
         states = Lrama::States.new(grammar, warning)
         states.compute
         counterexamples = Lrama::Counterexamples.new(states)
diff --git a/spec/lrama/new_parser_spec.rb b/spec/lrama/parser_spec.rb
similarity index 98%
rename from spec/lrama/new_parser_spec.rb
rename to spec/lrama/parser_spec.rb
index 6833ac0d..6bae8ace 100644
--- a/spec/lrama/new_parser_spec.rb
+++ b/spec/lrama/parser_spec.rb
@@ -1,4 +1,4 @@
-RSpec.describe Lrama::NewParser do
+RSpec.describe Lrama::Parser do
   T ||= Lrama::Lexer::Token
   Type = Lrama::Type
   Sym = Lrama::Grammar::Symbol
@@ -41,7 +41,7 @@
   describe '#parse' do
     it "basic" do
       y = File.read(fixture_path("common/basic.y"))
-      grammar = Lrama::NewParser.new(y).parse
+      grammar = Lrama::Parser.new(y).parse
 
       expect(grammar.union.code.s_value).to eq(<<-CODE.chomp)
 
@@ -408,7 +408,7 @@
 
     it "nullable" do
       y = File.read(fixture_path("common/nullable.y"))
-      grammar = Lrama::NewParser.new(y).parse
+      grammar = Lrama::Parser.new(y).parse
 
       expect(grammar.nterms.sort_by(&:number)).to eq([
         Sym.new(id: T.new(type: T::Ident, s_value: "$accept"),       alias_name: nil, number:  6, tag: nil, term: false, token_id: 0, nullable: false),
@@ -562,7 +562,7 @@ class : keyword_class tSTRING keyword_end { code 1 }
 %%
       INPUT
 
-      grammar = Lrama::NewParser.new(y).parse
+      grammar = Lrama::Parser.new(y).parse
 
       expect(grammar._rules).to eq([
         [
@@ -605,7 +605,7 @@ class : keyword_class tSTRING keyword_end { code 1 }
 %%
 
       INPUT
-      grammar = Lrama::NewParser.new(y).parse
+      grammar = Lrama::Parser.new(y).parse
 
       expect(grammar.terms.sort_by(&:number)).to eq([
         Sym.new(id: T.new(type: T::Ident, s_value: "EOI"),           alias_name: "\"EOI\"",           number:  0, tag: nil,                                   term: true, token_id:   0, nullable: false, precedence: nil),
@@ -661,7 +661,7 @@ class : keyword_class { code 1 } tSTRING { code 2 } keyword_end { code 3 }
 %%
 
       INPUT
-      grammar = Lrama::NewParser.new(y).parse
+      grammar = Lrama::Parser.new(y).parse
 
       expect(grammar.nterms.sort_by(&:number)).to eq([
         Sym.new(id: T.new(type: T::Ident, s_value: "$accept"), alias_name: nil, number: 11, tag: nil,                                 term: false, token_id: 0, nullable: false),
@@ -756,7 +756,7 @@ class : keyword_class tSTRING %prec tPLUS keyword_end { code 1 }
 %%
 
         INPUT
-        parser = Lrama::NewParser.new(y)
+        parser = Lrama::Parser.new(y)
 
         expect { parser.parse }.to raise_error("Ident after %prec")
       end
@@ -773,7 +773,7 @@ class : keyword_class { code 2 } tSTRING %prec "=" '!' keyword_end { code 3 }
 %%
 
         INPUT
-        parser = Lrama::NewParser.new(y)
+        parser = Lrama::Parser.new(y)
 
         expect { parser.parse }.to raise_error("Char after %prec")
       end
@@ -790,7 +790,7 @@ class : keyword_class { code 4 } tSTRING '?' keyword_end %prec tEQ { code 5 } {
 %%
 
         INPUT
-        parser = Lrama::NewParser.new(y)
+        parser = Lrama::Parser.new(y)
 
         expect { parser.parse }.to raise_error("Multiple User_code after %prec")
       end
@@ -811,7 +811,7 @@ class : keyword_class
 
 %%
         INPUT
-        grammar = Lrama::NewParser.new(y).parse
+        grammar = Lrama::Parser.new(y).parse
         codes = grammar.rules.map(&:code).compact
 
         expect(codes.count).to eq(1)
@@ -838,7 +838,7 @@ class : keyword_class
 
 %%
         INPUT
-        grammar = Lrama::NewParser.new(y).parse
+        grammar = Lrama::Parser.new(y).parse
         codes = grammar.rules.map(&:code).compact
 
         expect(codes.count).to eq(1)
@@ -883,7 +883,7 @@ class : keyword_class tSTRING keyword_end { code 1 }
 %%
 
         INPUT
-        grammar = Lrama::NewParser.new(y).parse
+        grammar = Lrama::Parser.new(y).parse
 
         expect(grammar.terms.sort_by(&:number)).to eq([
           Sym.new(id: T.new(type: T::Ident, s_value: "EOI"),           alias_name: "\"EOI\"",           number:  0, tag: nil,                                   term: true, token_id:   0, nullable: false),
@@ -932,7 +932,7 @@ class : keyword_class tSTRING keyword_end { code 1 }
 %%
 
         INPUT
-        grammar = Lrama::NewParser.new(y).parse
+        grammar = Lrama::Parser.new(y).parse
 
         expect(grammar.terms.sort_by(&:number)).to eq([
           Sym.new(id: T.new(type: T::Ident, s_value: "EOI"),           alias_name: "\"EOI\"",           number: 0, tag: nil,                                   term: true, token_id:   0, nullable: false, precedence: nil),
@@ -978,7 +978,7 @@ class : keyword_class tSTRING keyword_end { code 1 }
         ;
 %%
           INPUT
-          grammar = Lrama::NewParser.new(y).parse
+          grammar = Lrama::Parser.new(y).parse
 
           expect(grammar.rules).to eq([
             Rule.new(
@@ -1086,7 +1086,7 @@ class : keyword_class tSTRING keyword_end { code 1 }
    ;
 %%
           INPUT
-          grammar = Lrama::NewParser.new(y).parse
+          grammar = Lrama::Parser.new(y).parse
 
           expect(grammar.rules).to eq([
             Rule.new(
@@ -1177,7 +1177,7 @@ class : keyword_class tSTRING keyword_end { code 1 }
                 { $$ = $1 - $2; }
 ;
             INPUT
-            grammar = Lrama::NewParser.new(y).parse
+            grammar = Lrama::Parser.new(y).parse
 
             expect(grammar.rules).to eq([
               Rule.new(
@@ -1311,7 +1311,7 @@ class : keyword_class tSTRING keyword_end { code 1 }
 ;
             INPUT
 
-            expect { Lrama::NewParser.new(y).parse }.to raise_error("'results' is invalid name.")
+            expect { Lrama::Parser.new(y).parse }.to raise_error("'results' is invalid name.")
           end
         end
       end
@@ -1348,7 +1348,7 @@ class : keyword_class tSTRING keyword_end ;
 
 %%
       INPUT
-      grammar = Lrama::NewParser.new(y).parse
+      grammar = Lrama::Parser.new(y).parse
       terms = grammar.terms.sort_by(&:number).map do |term|
         [term.id.s_value, term.token_id]
       end
@@ -1397,7 +1397,7 @@ class : keyword_class tSTRING keyword_end
 
 %%
         INPUT
-        grammar = Lrama::NewParser.new(y).parse
+        grammar = Lrama::Parser.new(y).parse
         codes = grammar.rules.map(&:code)
 
         expect(codes.count).to eq(3)
@@ -1444,7 +1444,7 @@ class : keyword_class tSTRING keyword_end
 %%
         INPUT
 
-        expect { Lrama::NewParser.new(y).parse }.to raise_error(RuntimeError) do |e|
+        expect { Lrama::Parser.new(y).parse }.to raise_error(RuntimeError) do |e|
           expect(e.message).to eq(<<~MSG.chomp)
             $$ of 'stmt' has no declared type
             $1 of 'stmt' has no declared type
diff --git a/spec/lrama/states_spec.rb b/spec/lrama/states_spec.rb
index 01e383e2..e46c3759 100644
--- a/spec/lrama/states_spec.rb
+++ b/spec/lrama/states_spec.rb
@@ -5,7 +5,7 @@
   describe '#compute' do
     it "basic" do
       y = File.read(fixture_path("common/basic.y"))
-      grammar = Lrama::NewParser.new(y).parse
+      grammar = Lrama::Parser.new(y).parse
       states = Lrama::States.new(grammar, warning)
       states.compute
 
@@ -298,7 +298,7 @@ class    go to state 5
 
     it '#State#accessing_symbol' do
       y = File.read(fixture_path("common/basic.y"))
-      grammar = Lrama::NewParser.new(y).parse
+      grammar = Lrama::Parser.new(y).parse
       states = Lrama::States.new(grammar, warning)
       states.compute
 
@@ -338,7 +338,7 @@ class    go to state 5
   describe '#reads_relation' do
     it do
       y = File.read(fixture_path("states/reads_relation.y"))
-      grammar = Lrama::NewParser.new(y).parse
+      grammar = Lrama::Parser.new(y).parse
       states = Lrama::States.new(grammar, warning)
       states.compute
 
@@ -605,7 +605,7 @@ class    go to state 5
   describe '#includes_relation' do
     it do
       y = File.read(fixture_path("states/includes_relation.y"))
-      grammar = Lrama::NewParser.new(y).parse
+      grammar = Lrama::Parser.new(y).parse
       states = Lrama::States.new(grammar, warning)
       states.compute
 
@@ -904,7 +904,7 @@ class    go to state 5
 
 %%
         INPUT
-        grammar = Lrama::NewParser.new(y).parse
+        grammar = Lrama::Parser.new(y).parse
         states = Lrama::States.new(grammar, warning)
         states.compute
 
@@ -973,7 +973,7 @@ class    go to state 5
 
 %%
         INPUT
-        grammar = Lrama::NewParser.new(y).parse
+        grammar = Lrama::Parser.new(y).parse
         states = Lrama::States.new(grammar, warning)
         states.compute
 
@@ -1063,7 +1063,7 @@ class    go to state 5
 
 %%
         INPUT
-        grammar = Lrama::NewParser.new(y).parse
+        grammar = Lrama::Parser.new(y).parse
         states = Lrama::States.new(grammar, warning)
         states.compute
 
@@ -1180,7 +1180,7 @@ class    go to state 5
 
 %%
         INPUT
-        grammar = Lrama::NewParser.new(y).parse
+        grammar = Lrama::Parser.new(y).parse
         states = Lrama::States.new(grammar, warning)
         states.compute
 
@@ -1277,7 +1277,7 @@ class    go to state 5
 
 %%
         INPUT
-        grammar = Lrama::NewParser.new(y).parse
+        grammar = Lrama::Parser.new(y).parse
         states = Lrama::States.new(grammar, warning)
         states.compute
 
@@ -1426,7 +1426,7 @@ class    go to state 5
 
 %%
       INPUT
-      grammar = Lrama::NewParser.new(y).parse
+      grammar = Lrama::Parser.new(y).parse
       states = Lrama::States.new(grammar, warning)
       states.compute
 
@@ -1598,7 +1598,7 @@ class    go to state 5
 
 %%
       INPUT
-      grammar = Lrama::NewParser.new(y).parse
+      grammar = Lrama::Parser.new(y).parse
       states = Lrama::States.new(grammar, warning)
       states.compute
 
@@ -1816,7 +1816,7 @@ class : keyword_class tSTRING keyword_end %prec tPLUS
           end
 
           it "has errors for r/r conflicts" do
-            grammar = Lrama::NewParser.new(header + y).parse
+            grammar = Lrama::Parser.new(header + y).parse
             states = Lrama::States.new(grammar, warning)
             states.compute
 
@@ -1840,7 +1840,7 @@ class : keyword_class tSTRING keyword_end %prec tPLUS
           end
 
           it "has errors for s/r conflicts and r/r conflicts" do
-            grammar = Lrama::NewParser.new(header + y).parse
+            grammar = Lrama::Parser.new(header + y).parse
             states = Lrama::States.new(grammar, warning)
             states.compute
 
@@ -1864,7 +1864,7 @@ class : keyword_class tSTRING keyword_end %prec tPLUS
         end
 
         it "has warns for s/r conflicts and r/r conflicts" do
-          grammar = Lrama::NewParser.new(header + y).parse
+          grammar = Lrama::Parser.new(header + y).parse
           states = Lrama::States.new(grammar, warning)
           states.compute
 
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index b00d8b69..fe7e706f 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -6,7 +6,7 @@
   # Created Groups based on the folder structures
   add_group "Grammar", "lib/lrama/grammar"
   add_group "Lexer", "lib/lrama/lexer"
-  # add_group "Parser", "lib/lrama/parser"
+  add_group "Parser", "lib/lrama/parser"
   add_group "Report", "lib/lrama/report"
   add_group "State", "lib/lrama/state/"
   add_group "States", "lib/lrama/states/"