diff --git a/Gemfile.lock b/Gemfile.lock
index 9fe2291..eb0892c 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -15,8 +15,6 @@ GEM
     chartkick (3.3.1)
     concurrent-ruby (1.1.6)
     ffi (1.12.2)
-    groupdate (5.0.0)
-      activesupport (>= 5)
     httparty (0.18.0)
       mime-types (~> 3.0)
       multi_xml (>= 0.5.2)
@@ -32,7 +30,7 @@ GEM
     multi_xml (0.6.0)
     mustermann (1.1.1)
       ruby2_keywords (~> 0.0.1)
-    rack (2.2.2)
+    rack (2.2.3)
     rack-protection (2.0.8.1)
       rack
     rake (13.0.1)
@@ -65,7 +63,6 @@ PLATFORMS
 DEPENDENCIES
   activerecord
   chartkick
-  groupdate
   rake
   rerun
   sinatra