1 files changed, 1 insertions, 1 deletions
diff --git a/Gemfile b/Gemfile
index 5077c257d9..75a917e9cf 100644
--- a/Gemfile
+++ b/Gemfile
@@ -42,7 +42,7 @@ gem "json", ">= 2.0.0"
 gem "rubocop", ">= 0.47", require: false
 
 group :doc do
-  gem "sdoc", "1.0.0.rc1"
+  gem "sdoc", "> 1.0.0.rc1", "< 2.0"
   gem "redcarpet", "~> 3.2.3", platforms: :ruby
   gem "w3c_validators"
   gem "kindlerb", "~> 1.2.0"