diff --git a/README.md b/README.md
index 7da1a1e..4f59b66 100644
--- a/README.md
+++ b/README.md
@@ -70,5 +70,6 @@ mysql --user=partdb --password=password --database=partdb < schema.sql
 
 put the database access information in `credentials.json` and run `server.rb`.
 now go to http://localhost:4244 and you are ready to use it.
+the port is defined in `server.rb`.
 
 use a proxy web server to handle the authentication, TLS, compression, ...
diff --git a/server.rb b/server.rb
index 037d40d..d7482b9 100755
--- a/server.rb
+++ b/server.rb
@@ -26,6 +26,8 @@ CREDENTIALS = "credentials.json"
 PUBLIC = "public"
 # folder name for part attachments (in PUBLIC)
 ATTACHMENTS = "attachments"
+# port for this service
+PORT = 4244
 
 raise "database information #{CREDENTIALS} do not exist" unless File.file? CREDENTIALS
 
@@ -42,7 +44,7 @@ configure do
   set :protection, :except => :json_csrf
 
   set :bind, 'localhost'
-  set :port, 4244
+  set :port, PORT
   set :public_folder, "public"
   set :static, true
 end