diff --git a/common/onion.c b/common/onion.c
index 3fb4600f6..18ba5e806 100644
--- a/common/onion.c
+++ b/common/onion.c
@@ -201,7 +201,7 @@ struct onion_payload *onion_decode(const tal_t *ctx,
 				   const struct route_step *rs,
 				   const struct pubkey *blinding,
 				   const struct secret *blinding_ss,
-				   u64 *accepted_extra_tlvs,
+				   const u64 *accepted_extra_tlvs,
 				   u64 *failtlvtype,
 				   size_t *failtlvpos)
 {
diff --git a/common/onion.h b/common/onion.h
index bf8c3c430..46ccacb27 100644
--- a/common/onion.h
+++ b/common/onion.h
@@ -69,7 +69,7 @@ struct onion_payload *onion_decode(const tal_t *ctx,
 				   const struct route_step *rs,
 				   const struct pubkey *blinding,
 				   const struct secret *blinding_ss,
-				   u64 *accepted_extra_tlvs,
+				   const u64 *accepted_extra_tlvs,
 				   u64 *failtlvtype,
 				   size_t *failtlvpos);
 
diff --git a/wallet/test/run-wallet.c b/wallet/test/run-wallet.c
index 6a74d2bab..1bbdaf84f 100644
--- a/wallet/test/run-wallet.c
+++ b/wallet/test/run-wallet.c
@@ -536,7 +536,7 @@ struct onion_payload *onion_decode(const tal_t *ctx UNNEEDED,
 				   const struct route_step *rs UNNEEDED,
 				   const struct pubkey *blinding UNNEEDED,
 				   const struct secret *blinding_ss UNNEEDED,
-				   u64 *accepted_extra_tlvs UNNEEDED,
+				   const u64 *accepted_extra_tlvs UNNEEDED,
 				   u64 *failtlvtype UNNEEDED,
 				   size_t *failtlvpos UNNEEDED)
 { fprintf(stderr, "onion_decode called!\n"); abort(); }