diff --git a/Gemfile.lock b/Gemfile.lock
index a68ea510..8d6d7841 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -258,7 +258,7 @@ GEM
     minitest (5.20.0)
     msgpack (1.7.2)
     mutex_m (0.2.0)
-    net-imap (0.4.8)
+    net-imap (0.4.9)
       date
       net-protocol
     net-pop (0.1.2)