diff --git a/ChangeLog b/ChangeLog
index 47f26fa0..2cbbba93 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -11,6 +11,10 @@ ver. 1.1.2-dev-1 (20??/??/??) - development nightly edition
 -----------
 
 ### Fixes
+* backend `pyinotify`: fixes monitoring on systems with native inotify other than Linux (e. g. FreeBSD 15+),
+  where the parent directory of the log could not be watched (`EINVAL` for output-only flag `IN_ISDIR` in the mask),
+  so log rotation was not detected and the jail silently stopped to find failures; also removal of a log file
+  is detected now without relying on `IN_IGNORED` (not sent there for a watched file) (gh-4250)
 * `filter.d/postfix.conf` - monitor all Postfix instances in `system-postfix.slice` with the systemd backend (gh-4008)
 * `filter.d/nginx-botsearch.conf` - error-log regex extended with support of journal format (gh-3732)
 * `filter.d/apache-noscript.conf` - match a request for the `cgi-bin` directory itself (no script name after it),
diff --git a/fail2ban/server/filterpyinotify.py b/fail2ban/server/filterpyinotify.py
index 319314b7..99943973 100644
--- a/fail2ban/server/filterpyinotify.py
+++ b/fail2ban/server/filterpyinotify.py
@@ -243,10 +243,16 @@ class FilterPyinotify(FileFilter):
 	def _addDirWatcher(self, path_dir):
 		# Add watch for the directory:
 		if path_dir not in self.__watchDirs:
+			# note: IN_ISDIR is an output flag only (set in events by kernel), it must not be
+			# specified in the mask, since some systems reject it with EINVAL (e. g. FreeBSD 15+,
+			# with native inotify), so the directory would be not monitored at all (gh-4250);
+			# IN_ONLYDIR (input flag) to watch the path only if it is a directory;
+			# IN_DELETE and IN_MOVED_FROM to notice removal of watched files in the directory, since
+			# not all systems send IN_IGNORED for the watch of a removed file (e. g. FreeBSD):
 			self.__watchDirs.update(
-				self.__monitor.add_watch(path_dir, pyinotify.IN_CREATE | 
-					pyinotify.IN_MOVED_TO | pyinotify.IN_MOVE_SELF |
-					pyinotify.IN_DELETE_SELF | pyinotify.IN_ISDIR))
+				self.__monitor.add_watch(path_dir, pyinotify.IN_CREATE |
+					pyinotify.IN_MOVED_TO | pyinotify.IN_DELETE | pyinotify.IN_MOVED_FROM |
+					pyinotify.IN_MOVE_SELF | pyinotify.IN_DELETE_SELF | pyinotify.IN_ONLYDIR))
 			logSys.debug("Added monitor for the parent directory %s", path_dir)
 
 	def _delDirWatcher(self, path_dir):