diff --git a/sbin/geom/class/nop/gnop.8 b/sbin/geom/class/nop/gnop.8
index d1132075013e..54cad18965ba 100644
--- a/sbin/geom/class/nop/gnop.8
+++ b/sbin/geom/class/nop/gnop.8
@@ -107,7 +107,7 @@ Force the removal of the specified provider.
 Specifies failure probability in percentage.
 .It Fl o Ar offset
 Where to begin on the original provider.
-.It Fl o Ar size
+.It Fl s Ar size
 Size of the transparent provider.
 .It Fl v
 Be more verbose.