diff --git a/lib/protobuf/version.rb b/lib/protobuf/version.rb
index 0f3c9517..6e6da081 100644
--- a/lib/protobuf/version.rb
+++ b/lib/protobuf/version.rb
@@ -1,3 +1,3 @@
 module Protobuf
-  VERSION = '3.6.5'
+  VERSION = '3.6.6'
 end