diff --git a/Gemfile.lock b/Gemfile.lock
index 02e8175..4b487c4 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -143,7 +143,7 @@ GEM
     mocha (2.1.0)
       ruby2_keywords (>= 0.0.5)
     msgpack (1.7.2)
-    net-imap (0.3.7)
+    net-imap (0.4.0)
       date
       net-protocol
     net-pop (0.1.2)