diff --git a/lib/review/epubmaker.rb b/lib/review/epubmaker.rb
index e1420da3c..6e1887131 100644
--- a/lib/review/epubmaker.rb
+++ b/lib/review/epubmaker.rb
@@ -504,25 +504,32 @@ def copy_stylesheet(basetmpdir)
 
       @config['stylesheet'].each do |sfile|
         unless File.exist?(sfile)
-          error "#{sfile} is not found."
+          error "stylesheet: #{sfile} is not found."
         end
         FileUtils.cp(sfile, basetmpdir)
         @producer.contents.push(ReVIEW::EPUBMaker::Content.new(file: sfile))
       end
     end
 
+    def copy_static_file(configname, destdir, destfilename: nil)
+      destfilename ||= @config[configname]
+      unless File.exist?(@config[configname])
+        error "#{configname}: #{@config[configname]} is not found."
+      end
+      FileUtils.cp(@config[configname],
+                   File.join(destdir, destfilename))
+    end
+
     def copy_frontmatter(basetmpdir)
       if @config['cover'].present? && File.exist?(@config['cover'])
-        FileUtils.cp(@config['cover'],
-                     File.join(basetmpdir, File.basename(@config['cover'])))
+        copy_static_file('cover', basetmpdir)
       end
 
       if @config['titlepage']
         if @config['titlefile'].nil?
           build_titlepage(basetmpdir, "titlepage.#{@config['htmlext']}")
         else
-          FileUtils.cp(@config['titlefile'],
-                       File.join(basetmpdir, "titlepage.#{@config['htmlext']}"))
+          copy_static_file('titlefile', basetmpdir, destfilename: "titlepage.#{@config['htmlext']}")
         end
         @htmltoc.add_item(1,
                           "titlepage.#{@config['htmlext']}",
@@ -530,18 +537,16 @@ def copy_frontmatter(basetmpdir)
                           chaptype: 'pre')
       end
 
-      if @config['originaltitlefile'].present? && File.exist?(@config['originaltitlefile'])
-        FileUtils.cp(@config['originaltitlefile'],
-                     File.join(basetmpdir, File.basename(@config['originaltitlefile'])))
+      if @config['originaltitlefile'].present?
+        copy_static_file('originaltitlefile', basetmpdir)
         @htmltoc.add_item(1,
                           File.basename(@config['originaltitlefile']),
                           ReVIEW::I18n.t('originaltitle'),
                           chaptype: 'pre')
       end
 
-      if @config['creditfile'].present? && File.exist?(@config['creditfile'])
-        FileUtils.cp(@config['creditfile'],
-                     File.join(basetmpdir, File.basename(@config['creditfile'])))
+      if @config['creditfile'].present?
+        copy_static_file('creditfile', basetmpdir)
         @htmltoc.add_item(1,
                           File.basename(@config['creditfile']),
                           ReVIEW::I18n.t('credittitle'),
@@ -577,8 +582,7 @@ def build_titlepage(basetmpdir, htmlfile)
 
     def copy_backmatter(basetmpdir)
       if @config['profile']
-        FileUtils.cp(@config['profile'],
-                     File.join(basetmpdir, File.basename(@config['profile'])))
+        copy_static_file('profile', basetmpdir)
         @htmltoc.add_item(1,
                           File.basename(@config['profile']),
                           ReVIEW::I18n.t('profiletitle'),
@@ -586,8 +590,7 @@ def copy_backmatter(basetmpdir)
       end
 
       if @config['advfile']
-        FileUtils.cp(@config['advfile'],
-                     File.join(basetmpdir, File.basename(@config['advfile'])))
+        copy_static_file('advfile', basetmpdir)
         @htmltoc.add_item(1,
                           File.basename(@config['advfile']),
                           ReVIEW::I18n.t('advtitle'),
@@ -595,9 +598,8 @@ def copy_backmatter(basetmpdir)
       end
 
       if @config['colophon']
-        if @config['colophon'].is_a?(String) # FIXME: should let obsolete this style?
-          FileUtils.cp(@config['colophon'],
-                       File.join(basetmpdir, "colophon.#{@config['htmlext']}"))
+        if @config['colophon'].is_a?(String)
+          copy_static_file('colophon', basetmpdir, destfilename: "colophon.#{@config['htmlext']}") # override pre-built colophon
         end
         @htmltoc.add_item(1,
                           "colophon.#{@config['htmlext']}",
@@ -606,8 +608,7 @@ def copy_backmatter(basetmpdir)
       end
 
       if @config['backcover']
-        FileUtils.cp(@config['backcover'],
-                     File.join(basetmpdir, File.basename(@config['backcover'])))
+        copy_static_file('backcover', basetmpdir)
         @htmltoc.add_item(1,
                           File.basename(@config['backcover']),
                           ReVIEW::I18n.t('backcovertitle'),
diff --git a/lib/review/epubmaker/epubcommon.rb b/lib/review/epubmaker/epubcommon.rb
index 6371bc7c5..ee2e5fb1c 100644
--- a/lib/review/epubmaker/epubcommon.rb
+++ b/lib/review/epubmaker/epubcommon.rb
@@ -337,7 +337,9 @@ def produce_write_common(basedir, tmpdir)
           next if item.file =~ /#/ # skip subgroup
 
           fname = "#{basedir}/#{item.file}"
-          raise "#{fname} doesn't exist. Abort." unless File.exist?(fname)
+          unless File.exist?(fname)
+            raise "#{fname} is not found."
+          end
 
           FileUtils.mkdir_p(File.dirname("#{tmpdir}/OEBPS/#{item.file}"))
           FileUtils.cp(fname, "#{tmpdir}/OEBPS/#{item.file}")
diff --git a/test/test_epubmaker.rb b/test/test_epubmaker.rb
index ab5cfe47e..76de59e0d 100644
--- a/test/test_epubmaker.rb
+++ b/test/test_epubmaker.rb
@@ -865,4 +865,77 @@ def test_epub_unsafe_id
     content = ReVIEW::EPUBMaker::Content.new(file: 'sample-&()-=+@:,漢字.png')
     assert_equal 'sample-_25_26_25_28_25_29-_25_3D_25_2B_25_40_25_3A_25_2C_25_E6_25_BC_25_A2_25_E5_25_AD_25_97-png', content.id
   end
+
+  def epubmaker_instance
+    Dir.mktmpdir do |tmpdir|
+      epubmaker = ReVIEW::EPUBMaker.new
+      epubmaker.instance_eval do
+        @config = ReVIEW::Configure.create(maker: 'epubmaker')
+        @config['titlepage'] = nil
+        @producer = ReVIEW::EPUBMaker::Producer.new(@config)
+
+        @htmltoc = ReVIEW::HTMLToc.new(tmpdir)
+
+        def config
+          @config
+        end
+
+        def error(s)
+          raise ApplicationError, s
+        end
+      end
+
+      File.write(File.join(tmpdir, 'exist.css'), 'body {}')
+      File.write(File.join(tmpdir, 'exist.html'), '<html></html>')
+
+      Dir.chdir(tmpdir) do
+        Dir.mkdir('test')
+        yield(epubmaker, File.join(tmpdir, 'test'))
+      end
+    end
+  end
+
+  def test_copy_static_file
+    epubmaker_instance do |epubmaker, tmpdir|
+      epubmaker.config['stylesheet'] = ['exist.css']
+      assert_nothing_raised { epubmaker.copy_stylesheet(tmpdir) }
+
+      epubmaker.config['stylesheet'] = ['nothing.css']
+      e = assert_raise(ApplicationError) { epubmaker.copy_stylesheet(tmpdir) }
+      assert_equal 'stylesheet: nothing.css is not found.', e.message
+    end
+
+    epubmaker_instance do |epubmaker, tmpdir|
+      epubmaker.config['titlepage'] = true
+      epubmaker.config['titlefile'] = 'exist.html'
+      assert_nothing_raised { epubmaker.copy_frontmatter(tmpdir) }
+
+      epubmaker.config['titlefile'] = 'nothing.html'
+      e = assert_raise(ApplicationError) { epubmaker.copy_frontmatter(tmpdir) }
+      assert_equal 'titlefile: nothing.html is not found.', e.message
+    end
+
+    # XXX: only `cover' is allowed to have invalid file name.
+    %w[originaltitlefile creditfile].each do |name|
+      epubmaker_instance do |epubmaker, tmpdir|
+        epubmaker.config[name] = 'exist.html'
+        assert_nothing_raised { epubmaker.copy_frontmatter(tmpdir) }
+
+        epubmaker.config[name] = 'nothing.html'
+        e = assert_raise(ApplicationError) { epubmaker.copy_frontmatter(tmpdir) }
+        assert_equal "#{name}: nothing.html is not found.", e.message
+      end
+    end
+
+    %w[profile advfile colophon backcover].each do |name|
+      epubmaker_instance do |epubmaker, tmpdir|
+        epubmaker.config[name] = 'exist.html'
+        assert_nothing_raised { epubmaker.copy_backmatter(tmpdir) }
+
+        epubmaker.config[name] = 'nothing.html'
+        e = assert_raise(ApplicationError) { epubmaker.copy_backmatter(tmpdir) }
+        assert_equal "#{name}: nothing.html is not found.", e.message
+      end
+    end
+  end
 end