diff --git a/ssh_config.5 b/ssh_config.5
index 199fd6088..cd0eea867 100644
--- a/ssh_config.5
+++ b/ssh_config.5
@@ -33,8 +33,8 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.\" $OpenBSD: ssh_config.5,v 1.361 2021/08/06 05:04:42 dtucker Exp $
-.Dd $Mdocdate: August 6 2021 $
+.\" $OpenBSD: ssh_config.5,v 1.362 2021/08/12 23:59:25 djm Exp $
+.Dd $Mdocdate: August 12 2021 $
 .Dt SSH_CONFIG 5
 .Os
 .Sh NAME
@@ -377,11 +377,22 @@ Specifies which algorithms are allowed for signing of certificates
 by certificate authorities (CAs).
 The default is:
 .Bd -literal -offset indent
-ssh-ed25519,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,
-sk-ssh-ed25519@openssh.com,sk-ecdsa-sha2-nistp256@openssh.com,
+ssh-ed25519,ecdsa-sha2-nistp256,
+ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,
+sk-ssh-ed25519@openssh.com,
+sk-ecdsa-sha2-nistp256@openssh.com,
 rsa-sha2-512,rsa-sha2-256
 .Ed
 .Pp
+If the specified list begins with a
+.Sq +
+character, then the specified algorithms will be appended to the default set
+instead of replacing them.
+If the specified list begins with a
+.Sq -
+character, then the specified algorithms (including wildcards) will be removed
+from the default set instead of replacing them.
+.Pp
 .Xr ssh 1
 will not accept host certificates signed using algorithms other than those
 specified.
diff --git a/sshd_config.5 b/sshd_config.5
index a33280e1c..69d55206a 100644
--- a/sshd_config.5
+++ b/sshd_config.5
@@ -33,8 +33,8 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.\" $OpenBSD: sshd_config.5,v 1.333 2021/07/27 14:28:46 jmc Exp $
-.Dd $Mdocdate: July 27 2021 $
+.\" $OpenBSD: sshd_config.5,v 1.334 2021/08/12 23:59:25 djm Exp $
+.Dd $Mdocdate: August 12 2021 $
 .Dt SSHD_CONFIG 5
 .Os
 .Sh NAME
@@ -377,11 +377,22 @@ Specifies which algorithms are allowed for signing of certificates
 by certificate authorities (CAs).
 The default is:
 .Bd -literal -offset indent
-ssh-ed25519,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,
-sk-ssh-ed25519@openssh.com,sk-ecdsa-sha2-nistp256@openssh.com,
+ssh-ed25519,ecdsa-sha2-nistp256,
+ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,
+sk-ssh-ed25519@openssh.com,
+sk-ecdsa-sha2-nistp256@openssh.com,
 rsa-sha2-512,rsa-sha2-256
 .Ed
 .Pp
+If the specified list begins with a
+.Sq +
+character, then the specified algorithms will be appended to the default set
+instead of replacing them.
+If the specified list begins with a
+.Sq -
+character, then the specified algorithms (including wildcards) will be removed
+from the default set instead of replacing them.
+.Pp
 Certificates signed using other algorithms will not be accepted for
 public key or host-based authentication.
 .It Cm ChrootDirectory