diff --git a/NEWS.md b/NEWS.md
index d82263068c..f0eded8381 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -187,7 +187,7 @@ The following bundled gems are updated.
 * test-unit 3.6.1
 * rexml 3.2.6
 * rss 0.3.0
-* net-imap 0.4.5
+* net-imap 0.4.6
 * net-smtp 0.4.0
 * rbs 3.3.2
 * typeprof 0.21.8
diff --git a/gems/bundled_gems b/gems/bundled_gems
index b409c1cc9b..5fc893308e 100644
--- a/gems/bundled_gems
+++ b/gems/bundled_gems
@@ -12,7 +12,7 @@ test-unit       3.6.1   https://github.com/test-unit/test-unit
 rexml           3.2.6   https://github.com/ruby/rexml
 rss             0.3.0   https://github.com/ruby/rss
 net-ftp         0.2.0   https://github.com/ruby/net-ftp
-net-imap        0.4.5   https://github.com/ruby/net-imap
+net-imap        0.4.6   https://github.com/ruby/net-imap
 net-pop         0.1.2   https://github.com/ruby/net-pop
 net-smtp        0.4.0   https://github.com/ruby/net-smtp
 matrix          0.4.2   https://github.com/ruby/matrix