1 files changed, 1 insertions, 1 deletions
diff --git a/lib/test/unit.rb b/lib/test/unit.rb
index 7362beb889..729ddf6adf 100644
--- a/lib/test/unit.rb
+++ b/lib/test/unit.rb
@@ -32,7 +32,7 @@ module Test
       end
 
       files.map! {|f|
-        f.gsub!(/#{File::ALT_SEPARATOR}/o, File::SEPARATOR) if File::ALT_SEPARATOR
+        f = f.gsub(Regexp.compile(Regexp.quote(File::ALT_SEPARATOR)), File::SEPARATOR) if File::ALT_SEPARATOR
         if File.directory? f
           Dir["#{f}/**/test_*.rb"]
         elsif File.file? f