diff --git a/doc.go b/doc.go
index c7750158..88a12ee8 100644
--- a/doc.go
+++ b/doc.go
@@ -11,4 +11,4 @@ package mail
 
 // VERSION indicates the current version of the package. It is also attached to the default user
 // agent string.
-const VERSION = "0.5.0"
+const VERSION = "0.5.1"