diff --git a/pytest_marker_bugzilla.py b/pytest_marker_bugzilla.py
index 33b60a4..1ec07ac 100644
--- a/pytest_marker_bugzilla.py
+++ b/pytest_marker_bugzilla.py
@@ -326,21 +326,19 @@ def pytest_configure(config):
         "markers",
         "bugzilla(*bug_ids, **guards): Bugzilla integration",
     )
-    
-    bz = None
-    if config.getvalue("bugzilla") and config.getvalue('bugzilla_url'):
-        url = config.getvalue('bugzilla_url')
-        if config.getvalue('bugzilla_username') and config.getvalue('bugzilla_password'):
-            user = config.getvalue('bugzilla_username')
-            password = config.getvalue('bugzilla_password')
-            bz = bugzilla.Bugzilla(url=url, user=user, password=password)
-        elif config.getvalue('bugzilla_api_key'):
-            api_key = config.getvalue('bugzilla_api_key')
+
+    url = config.getvalue('bugzilla_url')
+    username = config.getvalue('bugzilla_username')
+    password = config.getvalue('bugzilla_password')
+    api_key = config.getvalue('bugzilla_api_key')
+    if config.getvalue("bugzilla") and url:
+        if username and password:
+            bz = bugzilla.Bugzilla(url=url, user=username, password=password)
+        elif api_key:
             bz = bugzilla.Bugzilla(url=url, api_key=api_key)
+        else:
+            bz = bugzilla.Bugzilla(url=url)
 
-        if not bz:
-            raise Exception('Please specify a valid bugzilla_username + bugzilla_password or a valid bugzilla_api_key')
-    
         version = config.getvalue('bugzilla_version')
         loose = [
             x.strip()