diff --git a/lib/lrama/option_parser.rb b/lib/lrama/option_parser.rb
index d8ed62ee..c73322ef 100644
--- a/lib/lrama/option_parser.rb
+++ b/lib/lrama/option_parser.rb
@@ -22,10 +22,10 @@ def parse(argv)
 
       if @options.grammar_file == '-'
         @options.grammar_file = argv.shift or abort "File name for STDIN should be specified\n"
-      else
-        @options.y = File.open(@options.grammar_file, 'r')
       end
 
+      @options.y = File.open(@options.grammar_file, 'r')
+
       if !@report.empty? && @options.report_file.nil? && @options.grammar_file
         @options.report_file = File.dirname(@options.grammar_file) + "/" + File.basename(@options.grammar_file, ".*") + ".output"
       end
diff --git a/spec/lrama/command_spec.rb b/spec/lrama/command_spec.rb
index 204faad8..abb20391 100644
--- a/spec/lrama/command_spec.rb
+++ b/spec/lrama/command_spec.rb
@@ -17,7 +17,7 @@
         File.open(fixture_path("command/basic.y")) do |f|
           allow(STDIN).to receive(:read).and_return(f.read)
           command = Lrama::Command.new
-          expect(command.run(o_option + ["-", "test.y"])).to be_nil
+          expect(command.run(o_option + ["-", fixture_path("command/basic.y")])).to be_nil
         end
       end
     end
diff --git a/spec/lrama/option_parser_spec.rb b/spec/lrama/option_parser_spec.rb
index 06432fdf..22aab83d 100644
--- a/spec/lrama/option_parser_spec.rb
+++ b/spec/lrama/option_parser_spec.rb
@@ -84,9 +84,9 @@
     context "file name is specified after '-'" do
       it "@grammar_file is file name" do
         option_parser = Lrama::OptionParser.new
-        option_parser.send(:parse, ["-", "test.y"])
+        option_parser.send(:parse, ["-", fixture_path("command/basic.y")])
         options = option_parser.instance_variable_get(:@options)
-        expect(options.grammar_file).to eq "test.y"
+        expect(options.grammar_file).to eq fixture_path("command/basic.y")
       end
     end
   end
@@ -95,7 +95,7 @@
     context "output option is not passed" do
       it "@outfile is default value" do
         option_parser = Lrama::OptionParser.new
-        option_parser.send(:parse, ["-", "test.y"])
+        option_parser.send(:parse, ["-", fixture_path("command/basic.y")])
         options = option_parser.instance_variable_get(:@options)
         expect(options.outfile).to eq "y.tab.c"
       end
@@ -104,7 +104,7 @@
     context "output option is passed" do
       it "@outfile is same with passed value" do
         option_parser = Lrama::OptionParser.new
-        option_parser.send(:parse, ["-o", "parse.c", "-", "test.y"])
+        option_parser.send(:parse, ["-o", "parse.c", "-", fixture_path("command/basic.y")])
         options = option_parser.instance_variable_get(:@options)
         expect(options.outfile).to eq "parse.c"
       end
@@ -116,7 +116,7 @@
       context "outfile option is passed" do
         it "@header_file is set based on outfile" do
           option_parser = Lrama::OptionParser.new
-          option_parser.send(:parse, ["-h", "-o", "parse.c", "-", "test.y"])
+          option_parser.send(:parse, ["-h", "-o", "parse.c", "-", fixture_path("command/basic.y")])
           options = option_parser.instance_variable_get(:@options)
           expect(options.header_file).to eq "./parse.h"
         end
@@ -125,7 +125,7 @@
       context "outfile option is not passed" do
         it "@header_file is set based on outfile default value" do
           option_parser = Lrama::OptionParser.new
-          option_parser.send(:parse, ["-h", "-", "test.y"])
+          option_parser.send(:parse, ["-h", "-", fixture_path("command/basic.y")])
           options = option_parser.instance_variable_get(:@options)
           expect(options.header_file).to eq "./y.tab.h"
         end
@@ -135,7 +135,7 @@
     context "header file name is passed" do
       it "@header_file is same with passed value" do
         option_parser = Lrama::OptionParser.new
-        option_parser.send(:parse, ["-hparse.h", "-", "test.y"])
+        option_parser.send(:parse, ["-hparse.h", "-", fixture_path("command/basic.y")])
         options = option_parser.instance_variable_get(:@options)
         expect(options.header_file).to eq "parse.h"
       end
@@ -151,9 +151,9 @@
         expect(options.report_file).to match(/command\/basic\.output/)
 
         option_parser = Lrama::OptionParser.new
-        option_parser.send(:parse, ["--report=all", "-", "test.y"])
+        option_parser.send(:parse, ["--report=all", "-", fixture_path("command/basic.y")])
         options = option_parser.instance_variable_get(:@options)
-        expect(options.report_file).to eq "./test.output"
+        expect(options.report_file).to eq fixture_path("command/basic.output")
       end
     end
 
@@ -165,7 +165,7 @@
         expect(options.report_file).to eq "report.output"
 
         option_parser = Lrama::OptionParser.new
-        option_parser.send(:parse, ["--report-file=report.output", "-", "test.y"])
+        option_parser.send(:parse, ["--report-file=report.output", "-", fixture_path("command/basic.y")])
         options = option_parser.instance_variable_get(:@options)
         expect(options.report_file).to eq "report.output"
       end