diff --git a/CHANGELOG.md b/CHANGELOG.md
index c925070..dc9f73f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Change log
 
+## unreleased
+
+### Fixed
+
+* Update the documentation to clarify that if patroni cannot be reached, we consider
+  it's a configuration error that returns UNKNOWN (#77, reported by @MLyssens)
+
 ## check_patroni 2.1.0 - 2024-10-19
 
 ### Fixed
diff --git a/README.md b/README.md
index b521c21..53e2d4f 100644
--- a/README.md
+++ b/README.md
@@ -140,6 +140,11 @@ example only Bash versions older than 4.4 are supported.
 
 [click]: https://click.palletsprojects.com/en/8.1.x/shell-completion/
 
+## Connection errors and service status
+
+If patroni is not running, we have no way to know if the provided endpoint is
+valid, therefore the check returns UNKNOWN.
+
 ## Cluster services
 
 ### cluster_config_has_changed
@@ -356,11 +361,14 @@ Options:
 Usage: check_patroni node_is_alive [OPTIONS]
 
   Check if the node is alive ie patroni is running. This is a liveness check
-  as defined in Patroni's documentation.
+  as defined in Patroni's documentation. If patroni is not running, we have no
+  way to know if the provided endpoint is valid, therefore the check returns
+  UNKNOWN.
 
   Check:
-  * `OK`: If patroni is running.
-  * `CRITICAL`: otherwise.
+  * `OK`: If patroni the liveness check returns with HTTP status 200.
+  * `CRITICAL`: if partoni's liveness check returns with an HTTP status
+     other than 200.
 
   Perfdata:
   * `is_running` is 1 if patroni is running, 0 otherwise
diff --git a/check_patroni/cli.py b/check_patroni/cli.py
index 6c35912..d9e880e 100644
--- a/check_patroni/cli.py
+++ b/check_patroni/cli.py
@@ -789,12 +789,15 @@ def node_patroni_version(ctx: click.Context, patroni_version: str) -> None:
 @nagiosplugin.guarded
 def node_is_alive(ctx: click.Context) -> None:
     """Check if the node is alive ie patroni is running. This is
-    a liveness check as defined in Patroni's documentation.
+    a liveness check as defined in Patroni's documentation. If
+    patroni is not running, we have no way to know if the provided
+    endpoint is valid, therefore the check returns UNKNOWN.
 
     \b
     Check:
-    * `OK`: If patroni is running.
-    * `CRITICAL`: otherwise.
+    * `OK`: If patroni the liveness check returns with HTTP status 200.
+    * `CRITICAL`: if partoni's liveness check returns with an HTTP status
+       other than 200.
 
     \b
     Perfdata:
diff --git a/check_patroni/types.py b/check_patroni/types.py
index 5f08dd4..a5548bc 100644
--- a/check_patroni/types.py
+++ b/check_patroni/types.py
@@ -11,8 +11,8 @@
 
 
 class APIError(requests.exceptions.RequestException):
-    """This exception is raised when the rest api couldn't
-    be reached and we got a http status code different from 200.
+    """This exception is raised when the rest api could
+    be reached but we got a http status code different from 200.
     """
 
 
diff --git a/docs/make_readme.sh b/docs/make_readme.sh
index 2c8f6d4..4544dd9 100755
--- a/docs/make_readme.sh
+++ b/docs/make_readme.sh
@@ -121,6 +121,11 @@ Please note that shell completion is not supported far all shell versions, for
 example only Bash versions older than 4.4 are supported.
 
 [click]: https://click.palletsprojects.com/en/8.1.x/shell-completion/
+
+## Connection errors and service status
+
+If patroni is not running, we have no way to know if the provided endpoint is
+valid, therefore the check returns UNKNOWN.
 _EOF_
 readme
 readme "## Cluster services"