diff --git a/lib/rexml/rexml.gemspec b/lib/rexml/rexml.gemspec
index 6fe7e635f1..263f013aae 100644
--- a/lib/rexml/rexml.gemspec
+++ b/lib/rexml/rexml.gemspec
@@ -64,7 +64,6 @@ Gem::Specification.new do |spec|
     "lib/rexml/security.rb",
     "lib/rexml/source.rb",
     "lib/rexml/streamlistener.rb",
-    "lib/rexml/syncenumerator.rb",
     "lib/rexml/text.rb",
     "lib/rexml/undefinednamespaceexception.rb",
     "lib/rexml/validation/relaxng.rb",