diff --git a/lib/adapter/api/droonga.js b/lib/adapter/api/droonga.js
index 4588d13..8e456cd 100644
--- a/lib/adapter/api/droonga.js
+++ b/lib/adapter/api/droonga.js
@@ -1,5 +1,7 @@
 var command = require('../command');
 
+var DEFAULT_TIMEOUT = 1000;
+
 function pathToMessageType(path) {
   return path
            .split('?')[0]
@@ -14,7 +16,7 @@ module.exports = {
     onRequest: function(request, connection) {
       var messageType = pathToMessageType(request.params[0]);
       var body = {};
-      body.timeout = body.timeout || 1000;
+      body.timeout = body.timeout || DEFAULT_TIMEOUT;
       connection.emit(messageType, body);
     }
   }),
@@ -30,7 +32,7 @@ module.exports = {
       });
       request.on('end', function() {
         body = JSON.parse(body);
-        body.timeout = body.timeout || 1000;
+        body.timeout = body.timeout || DEFAULT_TIMEOUT;
         body.type = body.type || 'droonga-' + messageType;
         connection.emit(messageType, body);
       });