diff --git a/lib/lrama/new_lexer.rb b/lib/lrama/new_lexer.rb
index 18b746d2..107c01c7 100644
--- a/lib/lrama/new_lexer.rb
+++ b/lib/lrama/new_lexer.rb
@@ -85,7 +85,7 @@ def lex_token
         return [:TAG, build_token(type: Token::Tag, s_value: @scanner.matched)]
       when @scanner.scan(/'.'/)
         return [:CHARACTER, build_token(type: Token::Char, s_value: @scanner.matched)]
-      when @scanner.scan(/'\\\\'|'\\t'|'\\f'|'\\r'|'\\n'|'\\13'/)
+      when @scanner.scan(/'\\\\'|'\\b'|'\\t'|'\\f'|'\\r'|'\\n'|'\\v'|'\\13'/)
         return [:CHARACTER, build_token(type: Token::Char, s_value: @scanner.matched)]
       when @scanner.scan(/"/)
         return [:STRING, %Q("#{@scanner.scan_until(/"/)})]
diff --git a/spec/lrama/new_parser_spec.rb b/spec/lrama/new_parser_spec.rb
index f61caae9..6833ac0d 100644
--- a/spec/lrama/new_parser_spec.rb
+++ b/spec/lrama/new_parser_spec.rb
@@ -851,7 +851,7 @@ class : keyword_class
     end
 
     describe "symbol number" do
-      xit "is not duplicated" do
+      it "is not duplicated" do
         y = <<~INPUT
 %{
 // Prologue
@@ -900,7 +900,7 @@ class : keyword_class tSTRING keyword_end { code 1 }
         ])
       end
 
-      xit "tokens after precedence declarations have greater number than tokens defined by precedence declarations" do
+      it "tokens after precedence declarations have greater number than tokens defined by precedence declarations" do
         y = <<~INPUT
 %{
 // Prologue
@@ -950,7 +950,7 @@ class : keyword_class tSTRING keyword_end { code 1 }
 
     describe "user codes" do
       describe "" do
-        xit "is not duplicated" do
+        it "is not duplicated" do
           y = <<~INPUT
 %{
 // Prologue
@@ -1060,7 +1060,7 @@ class : keyword_class tSTRING keyword_end { code 1 }
           ])
         end
 
-        xit "can parse action with %empty" do
+        it "can parse action with %empty" do
           y = <<~INPUT
 %{
 // Prologue
@@ -1146,7 +1146,7 @@ class : keyword_class tSTRING keyword_end { code 1 }
         end
 
         context "includes named references" do
-          xit "can parse" do
+          it "can parse" do
             y = <<~INPUT
 %{
 // Prologue
@@ -1279,7 +1279,7 @@ class : keyword_class tSTRING keyword_end { code 1 }
         end
 
         context "includes invalid named references" do
-          xit "raise an error" do
+          it "raise an error" do
             y = <<~INPUT
 %{
 // Prologue
@@ -1319,7 +1319,7 @@ class : keyword_class tSTRING keyword_end { code 1 }
   end
 
   describe "#fill_symbol_number" do
-    xit "fills token_id of Token::Char" do
+    it "fills token_id of Token::Char" do
       y = <<~INPUT
 %{
 // Prologue
@@ -1372,7 +1372,7 @@ class : keyword_class tSTRING keyword_end ;
 
   describe "#normalize_rules" do
     describe "referring_symbol" do
-      xit "uses a tag specified in code" do
+      it "uses a tag specified in code" do
         y = <<~INPUT
 %{
 // Prologue
@@ -1411,7 +1411,7 @@ class : keyword_class tSTRING keyword_end
 
   describe "Grammar#validate!" do
     describe "#validate_no_declared_type_reference!" do
-      xit "raises error when referred nterm, term and action have no tag so that type is not declared" do
+      it "raises error when referred nterm, term and action have no tag so that type is not declared" do
         y = <<~INPUT
 %{
 // Prologue