diff --git a/wayang-docs/src/main/resources/Gemfile.lock b/wayang-docs/src/main/resources/Gemfile.lock
index 683c2878b..413cf41dd 100644
--- a/wayang-docs/src/main/resources/Gemfile.lock
+++ b/wayang-docs/src/main/resources/Gemfile.lock
@@ -6,7 +6,7 @@ GEM
     asciidoctor (2.0.12)
     coderay (1.1.3)
     colorator (1.1.0)
-    concurrent-ruby (1.1.8)
+    concurrent-ruby (1.3.7)
     em-websocket (0.5.2)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0.6.0)