diff --git a/Gemfile b/Gemfile
index fe209a93..6802b3ce 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,4 @@
 source 'https://rubygems.org'
 
 gem 'kramdown-rfc'
-gem 'net-http-persistent'
+gem 'rexml', "<=3.2.6"
diff --git a/docker/action/Gemfile b/docker/action/Gemfile
index fe209a93..6802b3ce 100644
--- a/docker/action/Gemfile
+++ b/docker/action/Gemfile
@@ -1,4 +1,4 @@
 source 'https://rubygems.org'
 
 gem 'kramdown-rfc'
-gem 'net-http-persistent'
+gem 'rexml', "<=3.2.6"