diff --git a/docs/Gemfile b/docs/Gemfile
index 2d6d271..b073f51 100644
--- a/docs/Gemfile
+++ b/docs/Gemfile
@@ -7,7 +7,7 @@ end
 # Windows and JRuby does not include zoneinfo files, so bundle the tzinfo-data gem
 # and associated library.
 platforms :mingw, :x64_mingw, :mswin, :jruby do
-  gem "tzinfo", "~> 2.0"
+  gem "tzinfo", "~> 1.0"
   gem "tzinfo-data"
 end