diff --git a/lib/jenkins_api_client/client.rb b/lib/jenkins_api_client/client.rb
index cee4c2cb..8e4dab6c 100644
--- a/lib/jenkins_api_client/client.rb
+++ b/lib/jenkins_api_client/client.rb
@@ -129,7 +129,7 @@ def initialize(args)
       if @server_url
         server_uri = URI.parse(@server_url)
         @server_ip = server_uri.host
-        @server_port = server_uri.port
+        @server_port ||= server_uri.port
         @ssl = server_uri.scheme == "https"
         @jenkins_path = server_uri.path