diff --git a/lib/net/imap.rb b/lib/net/imap.rb
index ca194e58e1..2f3e39dd32 100644
--- a/lib/net/imap.rb
+++ b/lib/net/imap.rb
@@ -683,7 +683,7 @@ Struct
 
 require "socket"
 require "monitor"
-require "md5"
+require "digest/md5"
 
 module Net
   class IMAP