diff --git a/rubygem-xml-simple.spec b/rubygem-xml-simple.spec
index 0355296..b458601 100644
--- a/rubygem-xml-simple.spec
+++ b/rubygem-xml-simple.spec
@@ -1,34 +1,37 @@
-%global gem_name xml-simple
+%global	gem_name	xml-simple
 
-Name: rubygem-%{gem_name}
-Version: 1.1.8
-Release: 1%{?dist}
-Summary: A simple API for XML processing
-License: MIT
-URL: https://github.com/maik/xml-simple
-Source0: https://rubygems.org/gems/%{gem_name}-%{version}.gem
-Source1: %{gem_name}-tests-%{version}.tar.gz
+Name:		rubygem-%{gem_name}
+Version:	1.1.8
+Release:	1%{?dist}
+
+Summary:	A simple API for XML processing
+License:	MIT
+
+URL:		https://github.com/maik/xml-simple
+Source0:	https://rubygems.org/gems/%{gem_name}-%{version}.gem
+Source1:	%{gem_name}-tests-%{version}.tar.gz
 # Source1 is created from $ bash %%SOURCE2 <version> <githash>
-Source2: create-xml-simple-test-suite.sh
-BuildRequires: ruby(release)
-BuildRequires: rubygems-devel
-BuildRequires: ruby
+Source2:	create-xml-simple-test-suite.sh
+
+BuildRequires:	ruby(release)
+BuildRequires:	rubygems-devel
+BuildRequires:	ruby
 %if 0%{?fedora} >= 34
 # https://github.com/maik/xml-simple/pull/32
-BuildRequires: rubygem(rexml)
+BuildRequires:	rubygem(rexml)
 %endif
 # tests
-BuildRequires: rubygem(test-unit)
+BuildRequires:	rubygem(test-unit)
 
-BuildArch: noarch
+BuildArch:	noarch
 
 %description
 A simple API for XML processing.
 
-%package doc
-Summary: Documentation for %{name}
-Requires: %{name} = %{version}-%{release}
-BuildArch: noarch
+%package	doc
+Summary:	Documentation for %{name}
+Requires:	%{name} = %{version}-%{release}
+BuildArch:	noarch
 
 %description doc
 Documentation for %{name}.
@@ -49,7 +52,7 @@ gem build %{gem_name}-%{version}.gemspec
 %install
 mkdir -p %{buildroot}%{gem_dir}
 cp -a .%{gem_dir}/* \
-        %{buildroot}%{gem_dir}/
+	%{buildroot}%{gem_dir}/
 
 %check
 cp -a test .%{gem_instdir}
@@ -62,13 +65,13 @@ ruby -Ilib -e 'Dir.glob "./test/*.rb", &method(:require)'
 popd
 
 %files
-%dir %{gem_instdir}
+%dir	%{gem_instdir}
 %{gem_libdir}
 %exclude %{gem_cache}
 %{gem_spec}
 
 %files doc
-%doc %{gem_docdir}
+%doc	%{gem_docdir}
 
 %changelog
 * Tue Mar 30 2021 Mamoru TASAKA <mtasaka@fedoraproject.org> - 1.1.8-1