diff --git a/debian/postinst b/debian/postinst
index 300fdf46..af5ee097 100644
--- a/debian/postinst
+++ b/debian/postinst
@@ -25,6 +25,9 @@ case "$1" in
 				    sed -i '/^\s\+verify-schedule /d' /etc/proxmox-backup/datastore.cfg || true
 			fi
 		fi
+		if dpkg --compare-versions "$2" 'le' '0.9.5-1'; then
+			chown --quiet backup:backup /var/log/proxmox-backup/api/auth.log || true
+		fi
 	fi
 	# FIXME: Remove in future version once we're sure no broken entries remain in anyone's files
 	if grep -q -e ':termproxy::[^@]\+: ' /var/log/proxmox-backup/tasks/active; then
diff --git a/src/api2/access.rs b/src/api2/access.rs
index 9b9e85c0..3b59b3d3 100644
--- a/src/api2/access.rs
+++ b/src/api2/access.rs
@@ -12,7 +12,6 @@ use proxmox::{http_err, list_subdirs_api_method};
 use crate::tools::ticket::{self, Empty, Ticket};
 use crate::auth_helpers::*;
 use crate::api2::types::*;
-use crate::tools::{FileLogOptions, FileLogger};
 
 use crate::config::acl as acl_config;
 use crate::config::acl::{PRIVILEGES, PRIV_SYS_AUDIT, PRIV_PERMISSIONS_MODIFY};
@@ -144,20 +143,13 @@ fn create_ticket(
     port: Option<u16>,
     rpcenv: &mut dyn RpcEnvironment,
 ) -> Result<Value, Error> {
-    let logger_options = FileLogOptions {
-        append: true,
-        prefix_time: true,
-        ..Default::default()
-    };
-    let mut auth_log = FileLogger::new("/var/log/proxmox-backup/api/auth.log", logger_options)?;
-
     match authenticate_user(&username, &password, path, privs, port) {
         Ok(true) => {
             let ticket = Ticket::new("PBS", &username)?.sign(private_auth_key(), None)?;
 
             let token = assemble_csrf_prevention_token(csrf_secret(), &username);
 
-            auth_log.log(format!("successful auth for user '{}'", username));
+            crate::server::rest::auth_logger()?.log(format!("successful auth for user '{}'", username));
 
             Ok(json!({
                 "username": username,
@@ -180,7 +172,7 @@ fn create_ticket(
                 username,
                 err.to_string()
             );
-            auth_log.log(&msg);
+            crate::server::rest::auth_logger()?.log(&msg);
             log::error!("{}", msg);
 
             Err(http_err!(UNAUTHORIZED, "permission check failed."))
diff --git a/src/buildcfg.rs b/src/buildcfg.rs
index 402f2c9d..c7e65032 100644
--- a/src/buildcfg.rs
+++ b/src/buildcfg.rs
@@ -16,9 +16,14 @@ pub const PROXMOX_BACKUP_RUN_DIR: &str = PROXMOX_BACKUP_RUN_DIR_M!();
 /// namespaced directory for persistent logging
 pub const PROXMOX_BACKUP_LOG_DIR: &str = PROXMOX_BACKUP_LOG_DIR_M!();
 
-/// logfile for all API reuests handled by the proxy and privileged API daemons
+/// logfile for all API reuests handled by the proxy and privileged API daemons. Note that not all
+/// failed logins can be logged here with full information, use the auth log for that.
 pub const API_ACCESS_LOG_FN: &str = concat!(PROXMOX_BACKUP_LOG_DIR_M!(), "/api/access.log");
 
+/// logfile for any failed authentication, via ticket or via token, and new successfull ticket
+/// creations. This file can be useful for fail2ban.
+pub const API_AUTH_LOG_FN: &str = concat!(PROXMOX_BACKUP_LOG_DIR_M!(), "/api/auth.log");
+
 /// the PID filename for the unprivileged proxy daemon
 pub const PROXMOX_BACKUP_PROXY_PID_FN: &str = concat!(PROXMOX_BACKUP_RUN_DIR_M!(), "/proxy.pid");
 
diff --git a/src/server/rest.rs b/src/server/rest.rs
index 0749b891..ea87c9c8 100644
--- a/src/server/rest.rs
+++ b/src/server/rest.rs
@@ -164,6 +164,15 @@ fn log_response(
             ));
     }
 }
+pub fn auth_logger() -> Result<FileLogger, Error> {
+    let logger_options = tools::FileLogOptions {
+        append: true,
+        prefix_time: true,
+        owned_by_backup: true,
+        ..Default::default()
+    };
+    FileLogger::new(crate::buildcfg::API_AUTH_LOG_FN, logger_options)
+}
 
 fn get_proxied_peer(headers: &HeaderMap) -> Option<std::net::SocketAddr> {
     lazy_static! {
@@ -687,6 +696,10 @@ async fn handle_request(
                 match auth_result {
                     Ok(authid) => rpcenv.set_auth_id(Some(authid.to_string())),
                     Err(err) => {
+                        let peer = peer.ip();
+                        auth_logger()?
+                            .log(format!("authentication failure; rhost={} msg={}", peer, err));
+
                         // always delay unauthorized calls by 3 seconds (from start of request)
                         let err = http_err!(UNAUTHORIZED, "authentication failed - {}", err);
                         tokio::time::delay_until(Instant::from_std(delay_unauth_time)).await;