set module version to 1
diff --git a/src/couch_event_os_listener.erl b/src/couch_event_os_listener.erl
index 3ba5dcf..4de0a44 100644
--- a/src/couch_event_os_listener.erl
+++ b/src/couch_event_os_listener.erl
@@ -11,7 +11,8 @@
 % the License.
 
 -module(couch_event_os_listener).
--behavior(gen_server).
+-behaviour(gen_server).
+-vsn(1).
 
 
 -export([
diff --git a/src/couch_event_server.erl b/src/couch_event_server.erl
index 1c7bcf4..18509ec 100644
--- a/src/couch_event_server.erl
+++ b/src/couch_event_server.erl
@@ -11,7 +11,8 @@
 % the License.
 
 -module(couch_event_server).
--behavior(gen_server).
+-behaviour(gen_server).
+-vsn(1).
 
 
 -export([