diff --git a/src/openvpn/crypto.h b/src/openvpn/crypto.h
index 229a4eb1cde..846a7258d94 100644
--- a/src/openvpn/crypto.h
+++ b/src/openvpn/crypto.h
@@ -433,12 +433,6 @@ bool crypto_check_replay(struct crypto_options *opt,
                          struct gc_arena *gc);
 
 
-/** Calculate crypto overhead and adjust frame to account for that */
-void crypto_adjust_frame_parameters(struct frame *frame,
-                                    const struct key_type *kt,
-                                    bool packet_id,
-                                    bool packet_id_long_form);
-
 /** Calculate the maximum overhead that our encryption has
  * on a packet. This does not include needed additional buffer size
  *