diff --git a/README.md b/README.md
index 06659ff..d45d624 100644
--- a/README.md
+++ b/README.md
@@ -28,7 +28,7 @@ yum install python-enum34 python-requests
 The ``icinga2`` folder contains the command defintion and service examples for use with Icinga2.
 
 ```shell
-usage: check_opnsense.py [-h] -H HOSTNAME --api-key API_KEY --api-secret
+usage: check_opnsense.py [-h] -H HOSTNAME [-p PORT] --api-key API_KEY --api-secret
                          API_SECRET [-k] -m {updates} [-w TRESHOLD_WARNING]
                          [-c TRESHOLD_CRITICAL]
 
@@ -40,6 +40,8 @@ optional arguments:
 API Options:
   -H HOSTNAME, --hostname HOSTNAME
                         OPNsense hostname or ip address
+  -p PORT, --port PORT  OPNsense https-api port
+                        OPNsense hostname or ip address
   --api-key API_KEY     API key (See OPNsense user manager)
   --api-secret API_SECRET
                         API key (See OPNsense user manager)
diff --git a/check_opnsense.py b/check_opnsense.py
index 50792da..2d2cee7 100755
--- a/check_opnsense.py
+++ b/check_opnsense.py
@@ -51,7 +51,7 @@ class NagiosState(Enum):
 
 class CheckOPNsense:
     VERSION = '0.1.0'
-    API_URL = 'https://{}/api/{}'
+    API_URL = 'https://{}:{}/api/{}'
 
     options = {}
     perfdata = []
@@ -74,7 +74,7 @@ def output(self, returnCode, message):
         sys.exit(returnCode.value)
 
     def getURL(self, part):
-        return self.API_URL.format(self.options.hostname, part)
+        return self.API_URL.format(self.options.hostname, self.options.port, part)
 
     def request(self, url, method='get', **kwargs):
         response = None
@@ -134,6 +134,7 @@ def parseOptions(self):
         api_opts = p.add_argument_group('API Options')
 
         api_opts.add_argument("-H", "--hostname", required=True, help="OPNsense hostname or ip address")
+        api_opts.add_argument("-p", "--port", required=False, dest='port', help="OPNsense https-api port", default=80)
         api_opts.add_argument("--api-key", dest='api_key', required=True,
                               help="API key (See OPNsense user manager)")
         api_opts.add_argument("--api-secret", dest='api_secret', required=True,
@@ -178,3 +179,4 @@ def __init__(self):
 
 opnsense = CheckOPNsense()
 opnsense.check()
+