diff --git a/share/man/man9/pfil.9 b/share/man/man9/pfil.9
index c2186cf1b540..620d024bf8d1 100644
--- a/share/man/man9/pfil.9
+++ b/share/man/man9/pfil.9
@@ -144,7 +144,7 @@ Link-layer packets.
 .El
 .Pp
 Default rulesets are automatically linked to these heads to preserve
-historical behavavior.
+historical behaviour.
 .Sh SEE ALSO
 .Xr ipfilter 4 ,
 .Xr ipfw 4 ,