diff --git a/Gemfile.lock b/Gemfile.lock
index 87ea4fcc95c..2af1fa7814b 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -388,6 +388,7 @@ GEM
       danger-plugin-api (~> 1.0)
     danger-plugin-api (1.0.0)
       danger (> 2.0)
+    date (3.3.1)
     date_validator (0.12.0)
       activemodel (>= 3)
       activesupport (>= 3)
@@ -636,7 +637,8 @@ GEM
     mustermann-grape (1.0.2)
       mustermann (>= 1.0.0)
     nap (1.1.0)
-    net-imap (0.3.1)
+    net-imap (0.3.2)
+      date
       net-protocol
     net-ldap (0.17.1)
     net-pop (0.1.2)