diff --git a/surf.1 b/surf.1
index 45b75de..1c3e3d9 100644
--- a/surf.1
+++ b/surf.1
@@ -275,6 +275,9 @@ plugins
 .B m M
 styles
 .TP
+.B f F
+frame flattening
+.TP
 .B x X
 custom certificates
 .SH INDICATORS OF WEB PAGE