diff --git a/Gemfile.lock b/Gemfile.lock
index baa5809420aa..fb256e8f1d81 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -69,7 +69,8 @@ GEM
     mercenary (0.3.6)
     mini_portile2 (2.4.0)
     multi_json (1.13.1)
-    mustermann (1.0.3)
+    mustermann (1.1.2)
+      ruby2_keywords (~> 0.0.1)
     nokogiri (1.10.4)
       mini_portile2 (~> 2.4.0)
     pathutil (0.16.2)
@@ -85,6 +86,7 @@ GEM
     rouge (3.9.0)
     ruby-enum (0.7.2)
       i18n
+    ruby2_keywords (0.0.5)
     ruby_dep (1.5.0)
     safe_yaml (1.0.5)
     sass (3.4.25)