diff --git a/Gemfile.lock b/Gemfile.lock
index d52d6449c..15330321e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -57,7 +57,7 @@ GEM
     multi_xml (0.6.0)
     mustermann (3.0.0)
       ruby2_keywords (~> 0.0.1)
-    mutex_m (0.1.2)
+    mutex_m (0.2.0)
     nenv (0.3.0)
     notiffany (0.1.3)
       nenv (~> 0.1)