diff --git a/config/filter.d/sshd.conf b/config/filter.d/sshd.conf
index 691fb240..25bcba21 100644
--- a/config/filter.d/sshd.conf
+++ b/config/filter.d/sshd.conf
@@ -24,6 +24,7 @@ _daemon = sshd
 # Values:  TEXT
 #
 failregex = ^%(__prefix_line)s(?:error: PAM: )?Authentication failure for .* from <HOST>\s*$
+            ^%(__prefix_line)s(?:error: PAM: )?User not known to the underlying authentication module for .* from <HOST>\s*$
             ^%(__prefix_line)sFailed [-/\w]+ for .* from <HOST>(?: port \d*)?(?: ssh\d*)?$
             ^%(__prefix_line)sROOT LOGIN REFUSED.* FROM <HOST>\s*$
             ^%(__prefix_line)s[iI](?:llegal|nvalid) user .* from <HOST>\s*$