diff --git a/lib/fileutils.rb b/lib/fileutils.rb
index 1f38419..29be150 100644
--- a/lib/fileutils.rb
+++ b/lib/fileutils.rb
@@ -1491,7 +1491,8 @@ def remove_file(path, force = false)
   # Related: {methods for deleting}[rdoc-ref:FileUtils@Deleting].
   #
   def remove_dir(path, force = false)
-    remove_entry path, force   # FIXME?? check if it is a directory
+    raise Errno::ENOTDIR, path unless File.directory?(path)
+    remove_entry path, force
   end
   module_function :remove_dir
 
diff --git a/test/fileutils/test_fileutils.rb b/test/fileutils/test_fileutils.rb
index 1d7be69..95f3359 100644
--- a/test/fileutils/test_fileutils.rb
+++ b/test/fileutils/test_fileutils.rb
@@ -1763,6 +1763,14 @@ def test_remove_dir_file_perm
     assert_file_not_exist 'data/tmpdir'
   end if have_file_perm?
 
+  def test_remove_dir_with_file
+    File.write('data/tmpfile', 'dummy')
+    assert_raise(Errno::ENOTDIR) { remove_dir 'data/tmpfile' }
+    assert_file_exist 'data/tmpfile'
+  ensure
+    File.unlink('data/tmpfile') if File.exist?('data/tmpfile')
+  end
+
   def test_compare_file
     check_singleton :compare_file
     # FIXME