diff --git a/check-plugins/nextcloud-stats/README.md b/check-plugins/nextcloud-stats/README.md
index a176a778..8f20b190 100644
--- a/check-plugins/nextcloud-stats/README.md
+++ b/check-plugins/nextcloud-stats/README.md
@@ -29,23 +29,26 @@ Tested with Nextcloud 15+.
 
 ```text
 usage: nextcloud-stats [-h] [-V] [--insecure] [--no-proxy] --password PASSWORD
-                       [--timeout TIMEOUT] [--url URL] [--username USERNAME]
+                       [--timeout TIMEOUT] [--failure-is-critical] [--url URL]
+                       [--username USERNAME]
 
 This plugin lets you track the number of active users over time, the number of
 shares in various categories and some storage statistics against a Nextcloud
 server.
 
 options:
-  -h, --help           show this help message and exit
-  -V, --version        show program's version number and exit
-  --insecure           This option explicitly allows to perform "insecure" SSL
-                       connections. Default: False
-  --no-proxy           Do not use a proxy. Default: False
-  --password PASSWORD  Nextcloud API password.
-  --timeout TIMEOUT    Network timeout in seconds. Default: 8 (seconds)
-  --url URL            Nextcloud API URL. Default: http://localhost/nextcloud/
-                       ocs/v2.php/apps/serverinfo/api/v1/info
-  --username USERNAME  Nextcloud API username. Default: admin
+  -h, --help                 show this help message and exit
+  -V, --version              show program's version number and exit
+  --insecure                 This option explicitly allows to perform "insecure" SSL
+                             connections. Default: False
+  --no-proxy                 Do not use a proxy. Default: False
+  --password PASSWORD        Nextcloud API password.
+  --timeout TIMEOUT          Network timeout in seconds. Default: 8 (seconds)
+  --failure-is-critical      Return CRITICAL instead of UNKNOWN when any failure occurs
+                             (timeout, connection error, etc.). Default: False
+  --url URL                  Nextcloud API URL. Default: http://localhost/nextcloud/
+                             ocs/v2.php/apps/serverinfo/api/v1/info
+  --username USERNAME        Nextcloud API username. Default: admin
 ```
 
 
@@ -70,7 +73,9 @@ Output:
 
 ## States
 
-* Always returns OK.
+* Returns OK on success.
+* Returns UNKNOWN on errors (such as connection failures, DNS resolution errors, authentication errors, and timeouts by default).
+* Returns CRITICAL on any failure (timeout, connection error, etc.) when `--failure-is-critical` is used.
 
 
 ## Perfdata / Metrics
diff --git a/check-plugins/nextcloud-stats/nextcloud-stats b/check-plugins/nextcloud-stats/nextcloud-stats
index 2b66a224..ba4981e8 100755
--- a/check-plugins/nextcloud-stats/nextcloud-stats
+++ b/check-plugins/nextcloud-stats/nextcloud-stats
@@ -20,7 +20,7 @@ import lib.base  # pylint: disable=C0413
 import lib.human  # pylint: disable=C0413
 import lib.txt  # pylint: disable=C0413
 import lib.url  # pylint: disable=C0413
-from lib.globals import STATE_OK, STATE_UNKNOWN  # pylint: disable=C0413
+from lib.globals import STATE_OK, STATE_UNKNOWN, STATE_CRIT  # pylint: disable=C0413
 
 __author__ = 'Linuxfabrik GmbH, Zurich/Switzerland'
 __version__ = '2025100601'
@@ -81,6 +81,15 @@ def parse_args():
         default=DEFAULT_TIMEOUT,
     )
 
+    parser.add_argument(
+        '--failure-is-critical',
+        help='Return CRITICAL instead of UNKNOWN when any failure occurs (timeout, connection error, etc.). '
+             'Default: %(default)s',
+        dest='FAILURE_IS_CRITICAL',
+        action='store_true',
+        default=False,
+    )
+
     parser.add_argument(
         '--url',
         help='Nextcloud API URL. '
@@ -125,15 +134,28 @@ def main():
         'OCS-APIRequest': 'true',
     }
     # and get the info from the API
-    jsonst = lib.base.coe(
-        lib.url.fetch(
-            url,
-            header=header,
-            insecure=args.INSECURE,
-            no_proxy=args.NO_PROXY,
-            timeout=args.TIMEOUT,
-        )
+    fetch_result = lib.url.fetch(
+        url,
+        header=header,
+        insecure=args.INSECURE,
+        no_proxy=args.NO_PROXY,
+        timeout=args.TIMEOUT,
     )
+    # lib.url.fetch returns (False, error_message) on error, or the content on success
+    if isinstance(fetch_result, tuple) and len(fetch_result) == 2 and not fetch_result[0]:
+        # This is an error
+        error_message = fetch_result[1]
+        if args.FAILURE_IS_CRITICAL:
+            lib.base.oao(
+                'Connection failure occurred while fetching Nextcloud API data: {}'.format(error_message),
+                STATE_CRIT,
+            )
+            return  # Exit early, oao() should have already exited but just in case
+        # Let lib.base.coe() handle the error normally (will return UNKNOWN)
+        jsonst = lib.base.coe(fetch_result)
+    else:
+        # Success case
+        jsonst = lib.base.coe(fetch_result)
     try:
         result = json.loads(jsonst)
     except: