diff --git a/Makefile b/Makefile
index 50049aa09..7bdbc0119 100644
--- a/Makefile
+++ b/Makefile
@@ -253,6 +253,14 @@ config.vars:
 %.o: %.c
 	@$(call VERBOSE, "cc $<", $(CC) $(CFLAGS) -c -o $@ $<)
 
+# '_exp' inserted before _wiregen.[ch] to demark experimental
+# spec-derived headers, which are *not* committed into git.
+ifeq ($(EXPERIMENTAL_FEATURES),1)
+EXP := _exp
+else
+EXP :=
+endif
+
 # Git doesn't maintain timestamps, so we only regen if sources actually changed:
 # We place the SHA inside some generated files so we can tell if they need updating.
 # Usage: $(call SHA256STAMP_CHANGED)
@@ -262,16 +270,16 @@ SHA256STAMP = echo '$(1) SHA256STAMP:'`cat $(filter-out FORCE,$^) | sha256sum |
 
 # generate-wire.py --page [header|impl] hdrfilename wirename < csv > file
 %_wiregen.h: %_wire.csv $(WIRE_GEN_DEPS)
-	@if $(call SHA256STAMP_CHANGED); then $(call VERBOSE,"wiregen $@",tools/generate-wire.py --page header $($@_args) $@ `basename $< .csv` < $< > $@ && $(call SHA256STAMP,//)); fi
+	@if $(call SHA256STAMP_CHANGED); then $(call VERBOSE,"wiregen $@",tools/generate-wire.py --page header $($@_args) $@ `basename $< .csv | sed 's/_exp_/_/'` < $< > $@ && $(call SHA256STAMP,//)); fi
 
 %_wiregen.c: %_wire.csv $(WIRE_GEN_DEPS)
-	@if $(call SHA256STAMP_CHANGED); then $(call VERBOSE,"wiregen $@",tools/generate-wire.py --page impl $($@_args) ${@:.c=.h} `basename $< .csv` < $< > $@ && $(call SHA256STAMP,//)); fi
+	@if $(call SHA256STAMP_CHANGED); then $(call VERBOSE,"wiregen $@",tools/generate-wire.py --page impl $($@_args) ${@:.c=.h} `basename $< .csv | sed 's/_exp_/_/'` < $< > $@ && $(call SHA256STAMP,//)); fi
 
 %_printgen.h: %_wire.csv $(WIRE_GEN_DEPS)
-	@if $(call SHA256STAMP_CHANGED); then $(call VERBOSE,"printgen $@",tools/generate-wire.py -s -P --page header $($@_args) $@ `basename $< .csv` < $< > $@ && $(call SHA256STAMP,//)); fi
+	@if $(call SHA256STAMP_CHANGED); then $(call VERBOSE,"printgen $@",tools/generate-wire.py -s -P --page header $($@_args) $@ `basename $< .csv | sed 's/_exp_/_/'` < $< > $@ && $(call SHA256STAMP,//)); fi
 
 %_printgen.c: %_wire.csv $(WIRE_GEN_DEPS)
-	@if $(call SHA256STAMP_CHANGED); then $(call VERBOSE,"printgen $@",tools/generate-wire.py -s -P --page impl $($@_args) ${@:.c=.h} `basename $< .csv` < $< > $@ && $(call SHA256STAMP,//)); fi
+	@if $(call SHA256STAMP_CHANGED); then $(call VERBOSE,"printgen $@",tools/generate-wire.py -s -P --page impl $($@_args) ${@:.c=.h} `basename $< .csv | sed 's/_exp_/_/'` < $< > $@ && $(call SHA256STAMP,//)); fi
 
 include external/Makefile
 include bitcoin/Makefile
diff --git a/channeld/channeld.c b/channeld/channeld.c
index 07f48f898..95d8df756 100644
--- a/channeld/channeld.c
+++ b/channeld/channeld.c
@@ -63,7 +63,7 @@
 #include <sodium/crypto_aead_chacha20poly1305.h>
 #include <stdio.h>
 #include <wire/common_wiregen.h>
-#include <wire/onion_wiregen.h>
+#include <wire/onion_wire.h>
 #include <wire/peer_wire.h>
 #include <wire/wire.h>
 #include <wire/wire_io.h>
diff --git a/channeld/channeld_htlc.h b/channeld/channeld_htlc.h
index 5913a500e..118d9321f 100644
--- a/channeld/channeld_htlc.h
+++ b/channeld/channeld_htlc.h
@@ -6,7 +6,7 @@
 #include <common/amount.h>
 #include <common/htlc.h>
 #include <common/pseudorand.h>
-#include <wire/onion_wiregen.h>
+#include <wire/onion_wire.h>
 
 struct htlc {
 	/* What's the status. */
diff --git a/common/decode_array.c b/common/decode_array.c
index 37e482618..f2da3018d 100644
--- a/common/decode_array.c
+++ b/common/decode_array.c
@@ -1,7 +1,7 @@
 #include <ccan/cast/cast.h>
 #include <common/decode_array.h>
 #include <common/utils.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 #include <wire/wire.h>
 #include <zlib.h>
 
diff --git a/common/dev_disconnect.c b/common/dev_disconnect.c
index 13cfa3c79..b3d7c07ef 100644
--- a/common/dev_disconnect.c
+++ b/common/dev_disconnect.c
@@ -11,7 +11,7 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 
 #if DEVELOPER
 /* We move the fd if and only if we do a disconnect. */
diff --git a/common/gossip_rcvd_filter.c b/common/gossip_rcvd_filter.c
index 94f8ed4b7..05f0dae77 100644
--- a/common/gossip_rcvd_filter.c
+++ b/common/gossip_rcvd_filter.c
@@ -4,7 +4,7 @@
 #include <common/gossip_rcvd_filter.h>
 #include <common/memleak.h>
 #include <common/pseudorand.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 
 static u64 msg_key(const u8 *msg)
 {
diff --git a/common/gossip_store.c b/common/gossip_store.c
index 89a1c69d0..4d49bf396 100644
--- a/common/gossip_store.c
+++ b/common/gossip_store.c
@@ -9,7 +9,7 @@
 #include <errno.h>
 #include <inttypes.h>
 #include <unistd.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 
 void gossip_setup_timestamp_filter(struct per_peer_state *pps,
 				   u32 first_timestamp,
diff --git a/common/gossmap.c b/common/gossmap.c
index 1f51ebd61..ee46abae6 100644
--- a/common/gossmap.c
+++ b/common/gossmap.c
@@ -20,7 +20,7 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 
 /* We need this global to decode indexes for hash functions */
 static struct gossmap *map;
diff --git a/common/htlc_wire.h b/common/htlc_wire.h
index 743a743fb..e5d085e13 100644
--- a/common/htlc_wire.h
+++ b/common/htlc_wire.h
@@ -6,7 +6,7 @@
 #include <common/amount.h>
 #include <common/htlc.h>
 #include <common/sphinx.h>
-#include <wire/onion_wiregen.h>
+#include <wire/onion_wire.h>
 
 struct bitcoin_tx;
 struct shachain;
diff --git a/common/onion.c b/common/onion.c
index bd82eea7b..acb8b8ad7 100644
--- a/common/onion.c
+++ b/common/onion.c
@@ -5,7 +5,7 @@
 #include <common/ecdh.h>
 #include <common/sphinx.h>
 #include <sodium/crypto_aead_chacha20poly1305.h>
-#include <wire/onion_wiregen.h>
+#include <wire/onion_wire.h>
 
 /* BOLT #4:
  *
diff --git a/common/ping.c b/common/ping.c
index 5aed86670..8322e55a5 100644
--- a/common/ping.c
+++ b/common/ping.c
@@ -1,7 +1,7 @@
 #include <common/ping.h>
 #include <common/status.h>
 #include <common/version.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 
 bool check_ping_make_pong(const tal_t *ctx, const u8 *ping, u8 **pong)
 {
diff --git a/common/sphinx.h b/common/sphinx.h
index 18f924a7f..daad044e0 100644
--- a/common/sphinx.h
+++ b/common/sphinx.h
@@ -10,7 +10,7 @@
 #include <common/hmac.h>
 #include <secp256k1.h>
 #include <sodium/randombytes.h>
-#include <wire/onion_wiregen.h>
+#include <wire/onion_wire.h>
 
 struct node_id;
 
diff --git a/common/test/Makefile b/common/test/Makefile
index dfabba4d6..42065c669 100644
--- a/common/test/Makefile
+++ b/common/test/Makefile
@@ -13,7 +13,7 @@ ALL_C_SOURCES += $(COMMON_TEST_SRC)
 ALL_TEST_PROGRAMS += $(COMMON_TEST_PROGRAMS)
 
 # Sphinx test wants to decode TLVs.
-common/test/run-sphinx: wire/onion_wiregen.o wire/towire.o wire/fromwire.o
+common/test/run-sphinx: wire/onion$(EXP)_wiregen.o wire/towire.o wire/fromwire.o
 
 common/test/run-param					\
 common/test/run-json:					\
@@ -25,7 +25,7 @@ common/test/run-json:					\
 	common/wireaddr.o				\
 	common/type_to_string.o				\
 	wire/fromwire.o					\
-	wire/onion_wiregen.o				\
+	wire/onion$(EXP)_wiregen.o			\
 	wire/towire.o
 
 update-mocks: $(COMMON_TEST_SRC:%=update-mocks/%)
diff --git a/common/wire_error.c b/common/wire_error.c
index 537c51f02..67f6b773f 100644
--- a/common/wire_error.c
+++ b/common/wire_error.c
@@ -3,7 +3,7 @@
 #include <common/type_to_string.h>
 #include <common/utils.h>
 #include <common/wire_error.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 
 u8 *towire_errorfmtv(const tal_t *ctx,
 		     const struct channel_id *channel,
diff --git a/connectd/Makefile b/connectd/Makefile
index 5b4e34327..27cec25bb 100644
--- a/connectd/Makefile
+++ b/connectd/Makefile
@@ -63,7 +63,7 @@ CONNECTD_COMMON_OBJS :=				\
 	common/wire_error.o			\
 	gossipd/gossipd_wiregen.o		\
 	lightningd/gossip_msg.o			\
-	wire/onion_wiregen.o
+	wire/onion$(EXP)_wiregen.o
 
 lightningd/lightning_connectd: $(CONNECTD_OBJS) $(CONNECTD_COMMON_OBJS) $(BITCOIN_OBJS) $(WIRE_OBJS) $(HSMD_CLIENT_OBJS)
 
diff --git a/connectd/connectd.c b/connectd/connectd.c
index 1fcd9414d..069a73436 100644
--- a/connectd/connectd.c
+++ b/connectd/connectd.c
@@ -68,7 +68,6 @@
 #include <sys/un.h>
 #include <unistd.h>
 #include <wire/peer_wire.h>
-#include <wire/peer_wiregen.h>
 #include <wire/wire_io.h>
 #include <wire/wire_sync.h>
 #include <zlib.h>
diff --git a/devtools/Makefile b/devtools/Makefile
index ade001e35..d55ee1616 100644
--- a/devtools/Makefile
+++ b/devtools/Makefile
@@ -41,8 +41,8 @@ DEVTOOLS_COMMON_OBJS :=				\
 	common/utils.o				\
 	common/version.o			\
 	common/wireaddr.o			\
-	wire/onion_wiregen.o			\
-	wire/peer_wiregen.o
+	wire/onion$(EXP)_wiregen.o		\
+	wire/peer$(EXP)_wiregen.o
 
 devtools/bolt11-cli: $(DEVTOOLS_COMMON_OBJS) $(JSMN_OBJS) $(CCAN_OBJS) $(BITCOIN_OBJS) wire/fromwire.o wire/towire.o devtools/bolt11-cli.o
 
@@ -61,7 +61,7 @@ devtools/onion: $(DEVTOOLS_COMMON_OBJS) $(JSMN_OBJS) $(CCAN_OBJS) $(BITCOIN_OBJS
 
 devtools/blindedpath: $(DEVTOOLS_COMMON_OBJS) $(JSMN_OBJS) $(CCAN_OBJS) common/blinding.o $(BITCOIN_OBJS) wire/fromwire.o wire/towire.o devtools/blindedpath.o common/onion.o common/onionreply.o common/sphinx.o
 
-devtools/gossipwith: $(DEVTOOLS_COMMON_OBJS) $(JSMN_OBJS) $(CCAN_OBJS) $(BITCOIN_OBJS) wire/fromwire.o wire/towire.o wire/peer_wiregen.o devtools/gossipwith.o common/cryptomsg.o common/cryptomsg.o common/crypto_sync.o
+devtools/gossipwith: $(DEVTOOLS_COMMON_OBJS) $(JSMN_OBJS) $(CCAN_OBJS) $(BITCOIN_OBJS) wire/fromwire.o wire/towire.o wire/peer$(EXP)_wiregen.o devtools/gossipwith.o common/cryptomsg.o common/cryptomsg.o common/crypto_sync.o
 
 $(DEVTOOLS_OBJS) $(DEVTOOLS_TOOL_OBJS): wire/wire.h
 
diff --git a/devtools/create-gossipstore.c b/devtools/create-gossipstore.c
index a5699ad99..42c9db395 100644
--- a/devtools/create-gossipstore.c
+++ b/devtools/create-gossipstore.c
@@ -16,7 +16,7 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 
 
 struct scidsat {
diff --git a/devtools/decodemsg.c b/devtools/decodemsg.c
index 3bfd7d682..9e0650981 100644
--- a/devtools/decodemsg.c
+++ b/devtools/decodemsg.c
@@ -5,8 +5,13 @@
 #include <common/utils.h>
 #include <stdio.h>
 #include <unistd.h>
+#if EXPERIMENTAL_FEATURES
+#include <wire/onion_exp_printgen.h>
+#include <wire/peer_exp_printgen.h>
+#else
 #include <wire/onion_printgen.h>
 #include <wire/peer_printgen.h>
+#endif
 
 int main(int argc, char *argv[])
 {
diff --git a/devtools/dump-gossipstore.c b/devtools/dump-gossipstore.c
index 9d05be4dd..43759e4e7 100644
--- a/devtools/dump-gossipstore.c
+++ b/devtools/dump-gossipstore.c
@@ -12,7 +12,7 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 
 int main(int argc, char *argv[])
 {
diff --git a/devtools/mkgossip.c b/devtools/mkgossip.c
index 47fd81d70..9420e79f7 100644
--- a/devtools/mkgossip.c
+++ b/devtools/mkgossip.c
@@ -21,7 +21,7 @@
 #include <common/type_to_string.h>
 #include <common/utils.h>
 #include <inttypes.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 #include <stdio.h>
 
 static bool verbose = false;
diff --git a/devtools/mkquery.c b/devtools/mkquery.c
index b2f4911d5..27ca543f2 100644
--- a/devtools/mkquery.c
+++ b/devtools/mkquery.c
@@ -11,7 +11,7 @@
 #include <common/gossip_constants.h>
 #include <common/utils.h>
 #include <inttypes.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 #include <stdio.h>
 
 static void usage(void)
diff --git a/devtools/print_wire.h b/devtools/print_wire.h
index a7300119c..58c013f5b 100644
--- a/devtools/print_wire.h
+++ b/devtools/print_wire.h
@@ -3,8 +3,8 @@
 #include <bitcoin/preimage.h>
 #include <bitcoin/tx.h>
 #include <common/wireaddr.h>
-#include <wire/peer_wiregen.h>
-#include <wire/onion_wiregen.h>
+#include <wire/peer_wire.h>
+#include <wire/onion_wire.h>
 
 struct tlv_print_record_type {
 	u64 type;
diff --git a/gossipd/Makefile b/gossipd/Makefile
index 72c97eb7f..8deed147f 100644
--- a/gossipd/Makefile
+++ b/gossipd/Makefile
@@ -66,7 +66,7 @@ GOSSIPD_COMMON_OBJS :=				\
 	common/wire_error.o			\
 	connectd/connectd_gossipd_wiregen.o	\
 	lightningd/gossip_msg.o			\
-	wire/onion_wiregen.o
+	wire/onion$(EXP)_wiregen.o
 
 lightningd/lightning_gossipd: $(GOSSIPD_OBJS) $(GOSSIPD_COMMON_OBJS) $(BITCOIN_OBJS) $(WIRE_OBJS) $(HSMD_CLIENT_OBJS)
 
diff --git a/gossipd/gossip_generation.c b/gossipd/gossip_generation.c
index c4cea5c89..555a6150c 100644
--- a/gossipd/gossip_generation.c
+++ b/gossipd/gossip_generation.c
@@ -14,7 +14,7 @@
 #include <gossipd/gossipd.h>
 #include <gossipd/gossipd_peerd_wiregen.h>
 #include <hsmd/hsmd_wiregen.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 #include <wire/wire_sync.h>
 
 /* Create a node_announcement with the given signature. It may be NULL in the
diff --git a/gossipd/gossip_store.c b/gossipd/gossip_store.c
index 04396e7d3..ed085c380 100644
--- a/gossipd/gossip_store.c
+++ b/gossipd/gossip_store.c
@@ -18,7 +18,7 @@
 #include <sys/stat.h>
 #include <sys/uio.h>
 #include <unistd.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 #include <wire/wire.h>
 
 #define GOSSIP_STORE_FILENAME "gossip_store"
diff --git a/gossipd/gossipd.c b/gossipd/gossipd.c
index 0a6932b9d..7e48e3acf 100644
--- a/gossipd/gossipd.c
+++ b/gossipd/gossipd.c
@@ -63,7 +63,7 @@
 #include <sys/types.h>
 #include <sys/un.h>
 #include <unistd.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 #include <wire/wire_io.h>
 #include <wire/wire_sync.h>
 
diff --git a/gossipd/gossipd_wire.csv b/gossipd/gossipd_wire.csv
index b91aaf9a7..4433d104e 100644
--- a/gossipd/gossipd_wire.csv
+++ b/gossipd/gossipd_wire.csv
@@ -1,7 +1,7 @@
 #include <common/cryptomsg.h>
 #include <common/features.h>
 #include <common/wireaddr.h>
-#include <wire/onion_wiregen.h>
+#include <wire/onion_wire.h>
 
 # Initialize the gossip daemon.
 msgtype,gossipd_init,3000
diff --git a/gossipd/gossipd_wiregen.c b/gossipd/gossipd_wiregen.c
index cf7992ea4..7f88f336f 100644
--- a/gossipd/gossipd_wiregen.c
+++ b/gossipd/gossipd_wiregen.c
@@ -858,4 +858,4 @@ bool fromwire_gossipd_new_blockheight(const void *p, u32 *blockheight)
 	return cursor != NULL;
 }
 
-// SHA256STAMP:4aa62af856e3554603b0038eb0c9c6f5623cdb8d17abb6650338d1b728babd4b
+// SHA256STAMP:9ac18b60ff39a11d7871d17a660aa9661a49d2585abe25d0ba0e048c32ac02eb
diff --git a/gossipd/gossipd_wiregen.h b/gossipd/gossipd_wiregen.h
index 5361aa77b..83743247d 100644
--- a/gossipd/gossipd_wiregen.h
+++ b/gossipd/gossipd_wiregen.h
@@ -10,7 +10,7 @@
 #include <common/cryptomsg.h>
 #include <common/features.h>
 #include <common/wireaddr.h>
-#include <wire/onion_wiregen.h>
+#include <wire/onion_wire.h>
 #include <lightningd/gossip_msg.h>
 #include <common/bolt11.h>
 
@@ -200,4 +200,4 @@ bool fromwire_gossipd_new_blockheight(const void *p, u32 *blockheight);
 
 #endif /* LIGHTNING_GOSSIPD_GOSSIPD_WIREGEN_H */
 
-// SHA256STAMP:4aa62af856e3554603b0038eb0c9c6f5623cdb8d17abb6650338d1b728babd4b
+// SHA256STAMP:9ac18b60ff39a11d7871d17a660aa9661a49d2585abe25d0ba0e048c32ac02eb
diff --git a/gossipd/queries.c b/gossipd/queries.c
index 62e557066..64e4ab00e 100644
--- a/gossipd/queries.c
+++ b/gossipd/queries.c
@@ -15,7 +15,7 @@
 #include <gossipd/queries.h>
 #include <gossipd/routing.h>
 #include <gossipd/seeker.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 #include <wire/wire.h>
 #include <zlib.h>
 
diff --git a/gossipd/routing.c b/gossipd/routing.c
index 87f25e954..ff8c15d35 100644
--- a/gossipd/routing.c
+++ b/gossipd/routing.c
@@ -21,7 +21,7 @@
 #include <gossipd/gossipd_peerd_wiregen.h>
 #include <gossipd/gossipd_wiregen.h>
 #include <inttypes.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 
 #ifndef SUPERVERBOSE
 #define SUPERVERBOSE(...)
diff --git a/gossipd/routing.h b/gossipd/routing.h
index 6c0c1b53f..346a5995a 100644
--- a/gossipd/routing.h
+++ b/gossipd/routing.h
@@ -11,7 +11,7 @@
 #include <common/node_id.h>
 #include <gossipd/broadcast.h>
 #include <gossipd/gossip_store.h>
-#include <wire/onion_wiregen.h>
+#include <wire/onion_wire.h>
 #include <wire/wire.h>
 
 struct daemon;
diff --git a/gossipd/seeker.c b/gossipd/seeker.c
index 35656a2a1..79dda1dc7 100644
--- a/gossipd/seeker.c
+++ b/gossipd/seeker.c
@@ -17,7 +17,7 @@
 #include <gossipd/queries.h>
 #include <gossipd/routing.h>
 #include <gossipd/seeker.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 
 #define GOSSIP_SEEKER_INTERVAL(seeker) \
 	DEV_FAST_GOSSIP((seeker)->daemon->rstate->dev_fast_gossip, 5, 60)
diff --git a/gossipd/test/Makefile b/gossipd/test/Makefile
index 24d22f2ca..2deca9f07 100644
--- a/gossipd/test/Makefile
+++ b/gossipd/test/Makefile
@@ -17,7 +17,7 @@ GOSSIPD_TEST_COMMON_OBJS :=			\
 	common/pseudorand.o			\
 	common/type_to_string.o			\
 	common/utils.o				\
-	wire/peer_wiregen.o			\
+	wire/peer$(EXP)_wiregen.o		\
 	wire/fromwire.o				\
 	wire/towire.o
 
diff --git a/hsmd/hsmd.c b/hsmd/hsmd.c
index 63604b89b..f4bd92a90 100644
--- a/hsmd/hsmd.c
+++ b/hsmd/hsmd.c
@@ -51,7 +51,7 @@
 #include <sys/types.h>
 #include <unistd.h>
 #include <wally_bip32.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 #include <wire/wire_io.h>
 
 /*~ Each subdaemon is started with stdin connected to lightningd (for status
diff --git a/lightningd/connect_control.c b/lightningd/connect_control.c
index e2cdd3c56..bb5a57b2a 100644
--- a/lightningd/connect_control.c
+++ b/lightningd/connect_control.c
@@ -27,7 +27,7 @@
 #include <lightningd/opening_control.h>
 #include <lightningd/peer_control.h>
 #include <lightningd/subd.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 #include <wire/wire_sync.h>
 
 struct connect {
diff --git a/lightningd/gossip_control.c b/lightningd/gossip_control.c
index 071e8f67b..a3b608ff5 100644
--- a/lightningd/gossip_control.c
+++ b/lightningd/gossip_control.c
@@ -33,7 +33,7 @@
 #include <lightningd/ping.h>
 #include <sodium/randombytes.h>
 #include <string.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 #include <wire/wire_sync.h>
 
 static void got_txout(struct bitcoind *bitcoind,
diff --git a/lightningd/htlc_end.h b/lightningd/htlc_end.h
index 554350c7c..c502ce44a 100644
--- a/lightningd/htlc_end.h
+++ b/lightningd/htlc_end.h
@@ -7,7 +7,7 @@
 #include <common/amount.h>
 #include <common/htlc_state.h>
 #include <common/sphinx.h>
-#include <wire/onion_wiregen.h>
+#include <wire/onion_wire.h>
 
 /* We look up HTLCs by channel & id */
 struct htlc_key {
diff --git a/lightningd/htlc_set.h b/lightningd/htlc_set.h
index 3657df192..573a92d07 100644
--- a/lightningd/htlc_set.h
+++ b/lightningd/htlc_set.h
@@ -7,7 +7,7 @@
 #include <common/amount.h>
 #include <common/pseudorand.h>
 #include <common/utils.h>
-#include <wire/onion_wiregen.h>
+#include <wire/onion_wire.h>
 
 struct htlc_in;
 struct lightningd;
diff --git a/lightningd/invoice.h b/lightningd/invoice.h
index 1ccffda4a..4fba86064 100644
--- a/lightningd/invoice.h
+++ b/lightningd/invoice.h
@@ -1,7 +1,7 @@
 #ifndef LIGHTNING_LIGHTNINGD_INVOICE_H
 #define LIGHTNING_LIGHTNINGD_INVOICE_H
 #include "config.h"
-#include <wire/onion_wiregen.h>
+#include <wire/onion_wire.h>
 
 struct amount_msat;
 struct htlc_set;
diff --git a/lightningd/notification.h b/lightningd/notification.h
index a0b248e1f..940479887 100644
--- a/lightningd/notification.h
+++ b/lightningd/notification.h
@@ -17,7 +17,7 @@
 #include <lightningd/pay.h>
 #include <lightningd/plugin.h>
 #include <wallet/wallet.h>
-#include <wire/onion_wiregen.h>
+#include <wire/onion_wire.h>
 
 struct onionreply;
 
diff --git a/lightningd/peer_control.c b/lightningd/peer_control.c
index f956c8d7f..694447229 100644
--- a/lightningd/peer_control.c
+++ b/lightningd/peer_control.c
@@ -58,7 +58,7 @@
 #include <unistd.h>
 #include <wally_bip32.h>
 #include <wire/common_wiregen.h>
-#include <wire/onion_wiregen.h>
+#include <wire/onion_wire.h>
 #include <wire/wire_sync.h>
 
 struct close_command {
diff --git a/lightningd/peer_htlcs.c b/lightningd/peer_htlcs.c
index 4e737bbd4..5729b9172 100644
--- a/lightningd/peer_htlcs.c
+++ b/lightningd/peer_htlcs.c
@@ -36,7 +36,7 @@
 #include <lightningd/subd.h>
 #include <onchaind/onchaind_wiregen.h>
 #include <wallet/wallet.h>
-#include <wire/onion_wiregen.h>
+#include <wire/onion_wire.h>
 #include <wire/wire_sync.h>
 
 #ifndef SUPERVERBOSE
diff --git a/openingd/openingd.c b/openingd/openingd.c
index af5383404..3520e3b93 100644
--- a/openingd/openingd.c
+++ b/openingd/openingd.c
@@ -52,7 +52,6 @@
 #include <wally_bip32.h>
 #include <wire/common_wiregen.h>
 #include <wire/peer_wire.h>
-#include <wire/peer_wiregen.h>
 #include <wire/wire.h>
 #include <wire/wire_sync.h>
 
diff --git a/plugins/Makefile b/plugins/Makefile
index 27160ef77..b8512c5cf 100644
--- a/plugins/Makefile
+++ b/plugins/Makefile
@@ -82,7 +82,7 @@ PLUGIN_COMMON_OBJS :=				\
 	common/version.o			\
 	common/wireaddr.o			\
 	wire/fromwire.o				\
-	wire/onion_wiregen.o			\
+	wire/onion$(EXP)_wiregen.o		\
 	wire/tlvstream.o			\
 	wire/towire.o
 
@@ -95,7 +95,7 @@ plugins/fundchannel: common/addr.o $(PLUGIN_FUNDCHANNEL_OBJS) $(PLUGIN_LIB_OBJS)
 
 plugins/bcli: bitcoin/chainparams.o $(PLUGIN_BCLI_OBJS) $(PLUGIN_LIB_OBJS) $(PLUGIN_COMMON_OBJS) $(JSMN_OBJS) $(CCAN_OBJS)
 
-plugins/keysend: bitcoin/chainparams.o wire/tlvstream.o wire/onion_wiregen.o $(PLUGIN_KEYSEND_OBJS) $(PLUGIN_LIB_OBJS) $(PLUGIN_PAY_LIB_OBJS) $(PLUGIN_COMMON_OBJS) $(JSMN_OBJS) $(CCAN_OBJS)
+plugins/keysend: bitcoin/chainparams.o wire/tlvstream.o wire/onion$(EXP)_wiregen.o $(PLUGIN_KEYSEND_OBJS) $(PLUGIN_LIB_OBJS) $(PLUGIN_PAY_LIB_OBJS) $(PLUGIN_COMMON_OBJS) $(JSMN_OBJS) $(CCAN_OBJS)
 $(PLUGIN_KEYSEND_OBJS): $(PLUGIN_PAY_LIB_HEADER)
 
 $(PLUGIN_ALL_OBJS): $(PLUGIN_LIB_HEADER)
diff --git a/plugins/keysend.c b/plugins/keysend.c
index f21f51c32..40510ecc2 100644
--- a/plugins/keysend.c
+++ b/plugins/keysend.c
@@ -3,7 +3,7 @@
 #include <ccan/tal/str/str.h>
 #include <plugins/libplugin-pay.h>
 #include <plugins/libplugin.h>
-#include <wire/onion_wiregen.h>
+#include <wire/onion_wire.h>
 
 #define PREIMAGE_TLV_TYPE 5482373484
 #define KEYSEND_FEATUREBIT 55
diff --git a/plugins/libplugin-pay.h b/plugins/libplugin-pay.h
index 8c5b5dfe0..4fc270dd9 100644
--- a/plugins/libplugin-pay.h
+++ b/plugins/libplugin-pay.h
@@ -4,7 +4,7 @@
 
 #include <common/bolt11.h>
 #include <plugins/libplugin.h>
-#include <wire/onion_wiregen.h>
+#include <wire/onion_wire.h>
 
 struct legacy_payload {
 	struct short_channel_id scid;
diff --git a/tools/test/Makefile b/tools/test/Makefile
index 66cdcc816..73610102a 100644
--- a/tools/test/Makefile
+++ b/tools/test/Makefile
@@ -42,7 +42,7 @@ tools/test/gen_test.c.tmp.c: $(TOOLS_WIRE_DEPS)
 tools/test/gen_test.c: tools/test/gen_test.c.tmp.c $(EXTERNAL_HEADERS) tools/test/gen_test.h
 	@MAKE=$(MAKE) tools/update-mocks.sh "$<" $(SUPPRESS_OUTPUT) && mv "$<" "$@"
 
-tools/test/gen_print.h: wire/onion_wiregen.h $(TOOLS_WIRE_DEPS)
+tools/test/gen_print.h: wire/onion$(EXP)_wiregen.h $(TOOLS_WIRE_DEPS)
 	$(BOLT_GEN) -P --page header $@ test_type < tools/test/test_cases > $@
 
 tools/test/gen_print.c: $(TOOLS_WIRE_DEPS)
diff --git a/wallet/wallet.h b/wallet/wallet.h
index 18f38e79e..9c9566f8c 100644
--- a/wallet/wallet.h
+++ b/wallet/wallet.h
@@ -20,7 +20,7 @@
 #include <lightningd/log.h>
 #include <onchaind/onchaind_wire.h>
 #include <wally_bip32.h>
-#include <wire/onion_wiregen.h>
+#include <wire/onion_wire.h>
 
 struct amount_msat;
 struct invoices;
diff --git a/wire/Makefile b/wire/Makefile
index c0348e201..e1ee3c937 100644
--- a/wire/Makefile
+++ b/wire/Makefile
@@ -2,15 +2,16 @@
 
 WIRE_HEADERS :=	wire/onion_defs.h		\
 		wire/peer_wire.h		\
+		wire/onion_wire.h		\
 		wire/tlvstream.h		\
 		wire/wire.h			\
 		wire/wire_sync.h		\
 		wire/wire_io.h			\
-		wire/peer_wiregen.h		\
-		wire/onion_wiregen.h		\
+		wire/peer$(EXP)_wiregen.h	\
+		wire/onion$(EXP)_wiregen.h	\
 		wire/common_wiregen.h		\
-		wire/peer_printgen.h		\
-		wire/onion_printgen.h
+		wire/peer$(EXP)_printgen.h	\
+		wire/onion$(EXP)_printgen.h
 
 # We don't include peer_printgen/onion_printgen here since most don't need it.
 WIRE_SRC := wire/wire_sync.c			\
@@ -20,12 +21,12 @@ WIRE_SRC := wire/wire_sync.c			\
 		wire/tlvstream.c		\
 		wire/towire.c			\
 		wire/common_wiregen.c		\
-		wire/peer_wiregen.c		\
-		wire/onion_wiregen.c	
+		wire/peer$(EXP)_wiregen.c	\
+		wire/onion$(EXP)_wiregen.c	
 
 WIRE_PRINT_SRC :=				\
-		wire/onion_printgen.c		\
-		wire/peer_printgen.c
+		wire/onion$(EXP)_printgen.c	\
+		wire/peer$(EXP)_printgen.c
 
 WIRE_OBJS := $(WIRE_SRC:.c=.o)
 WIRE_PRINT_OBJS := $(WIRE_PRINT_SRC:.c=.o)
@@ -61,23 +62,13 @@ ifeq ($(EXPERIMENTAL_FEATURES),1)
 EXPERIMENTAL_PEER_PATCHES := $(sort $(wildcard wire/extracted_peer_experimental_*))
 EXPERIMENTAL_ONION_PATCHES := $(sort $(wildcard wire/extracted_onion_experimental_*))
 
-wire/peer_wire.csv: wire/extracted_peer_wire_csv $(EXPERIMENTAL_PEER_PATCHES)
+wire/peer_exp_wire.csv: wire/peer_wire_csv $(EXPERIMENTAL_PEER_PATCHES)
 	@set -e; trap "rm -f $@.$$$$" 0; cp $< $@.$$$$; for exp in $(EXPERIMENTAL_PEER_PATCHES); do patch $@.$$$$ $$exp >/dev/null ; done; mv $@.$$$$ $@
 
-wire/onion_wire.csv: wire/extracted_onion_wire_csv $(EXPERIMENTAL_ONION_PATCHES)
+wire/onion_exp_wire.csv: wire/onion_wire_csv $(EXPERIMENTAL_ONION_PATCHES)
 	@set -e; trap "rm -f $@.$$$$" 0; cp $< $@.$$$$; for exp in $(EXPERIMENTAL_ONION_PATCHES); do patch $@.$$$$ $$exp; done >/dev/null ; mv $@.$$$$ $@
-
-else # /* EXPERIMENTAL_FEATURES */
-wire/peer_wire.csv: wire/extracted_peer_wire_csv
-	@cp $< $@
-
-wire/onion_wire.csv: wire/extracted_onion_wire_csv
-	@cp $< $@
 endif
 
-# We (may) need to rebuild these if config changes
-wire/peer_wire.csv wire/onion_wire.csv: config.vars
-
 # tlvs_n1 and n2 are used for test vectors, thus not referenced: expose them
 # for testing and to prevent compile error about them being unused.
 # This will be easier if test vectors are moved to separate files.
@@ -90,6 +81,12 @@ wire/onion_wiregen.h_args := --include='bitcoin/short_channel_id.h' --include='b
 
 wire/onion_wiregen.c_args := -s --expose-tlv-type=tlv_payload
 
+# Same for _exp versions
+wire/peer_exp_wiregen.h_args := $(wire/peer_wiregen.h_args)
+wire/peer_exp_wiregen.c_args := $(wire/peer_wiregen.c_args)
+wire/onion_exp_wiregen.h_args := $(wire/onion_wiregen.h_args)
+wire/onion_exp_wiregen.c_args := $(wire/onion_wiregen.c_args)
+
 maintainer-clean: wire-maintainer-clean
 
 wire-maintainer-clean:
diff --git a/wire/onion_wire.h b/wire/onion_wire.h
new file mode 100644
index 000000000..63bea4684
--- /dev/null
+++ b/wire/onion_wire.h
@@ -0,0 +1,12 @@
+#ifndef LIGHTNING_WIRE_ONION_WIRE_H
+#define LIGHTNING_WIRE_ONION_WIRE_H
+#include "config.h"
+#include <stdbool.h>
+
+#if EXPERIMENTAL_FEATURES
+#include <wire/onion_exp_wiregen.h>
+#else
+#include <wire/onion_wiregen.h>
+#endif
+
+#endif /* LIGHTNING_WIRE_ONION_WIRE_H */
diff --git a/wire/extracted_onion_wire_csv b/wire/onion_wire_csv
similarity index 100%
rename from wire/extracted_onion_wire_csv
rename to wire/onion_wire_csv
diff --git a/wire/peer_wire.h b/wire/peer_wire.h
index 008410304..12c951b8f 100644
--- a/wire/peer_wire.h
+++ b/wire/peer_wire.h
@@ -2,7 +2,12 @@
 #define LIGHTNING_WIRE_PEER_WIRE_H
 #include "config.h"
 #include <stdbool.h>
+
+#if EXPERIMENTAL_FEATURES
+#include <wire/peer_exp_wiregen.h>
+#else
 #include <wire/peer_wiregen.h>
+#endif
 
 /* BOLT #1:
  *
diff --git a/wire/extracted_peer_wire_csv b/wire/peer_wire_csv
similarity index 100%
rename from wire/extracted_peer_wire_csv
rename to wire/peer_wire_csv
diff --git a/wire/test/Makefile b/wire/test/Makefile
index db7bf7a54..154f92ea3 100644
--- a/wire/test/Makefile
+++ b/wire/test/Makefile
@@ -21,4 +21,4 @@ $(WIRE_TEST_OBJS): $(WIRE_HEADERS) $(WIRE_SRC) $(WIRE_PRINT_SRC)
 
 wire-tests: $(WIRE_TEST_PROGRAMS:%=unittest/%)
 
-wire/test/run-peer-wire: wire/peer_wiregen.o common/bigsize.o
+wire/test/run-peer-wire: wire/peer$(EXP)_wiregen.o common/bigsize.o
diff --git a/wire/test/run-peer-wire.c b/wire/test/run-peer-wire.c
index c5b7e54f3..a9acefb93 100644
--- a/wire/test/run-peer-wire.c
+++ b/wire/test/run-peer-wire.c
@@ -14,7 +14,7 @@
 #include <common/bigsize.h>
 #include <bitcoin/chainparams.h>
 #include <common/sphinx.h>
-#include <wire/peer_wiregen.h>
+#include <wire/peer_wire.h>
 
 extern secp256k1_context *secp256k1_ctx;
 
diff --git a/wire/test/run-tlvstream.c b/wire/test/run-tlvstream.c
index dd05357c5..f7991edb6 100644
--- a/wire/test/run-tlvstream.c
+++ b/wire/test/run-tlvstream.c
@@ -13,7 +13,11 @@ static const char *reason;
 #include <common/bigsize.c>
 #include <common/node_id.c>
 
+#if EXPERIMENTAL_FEATURES
+#include <wire/peer_exp_wiregen.c>
+#else
 #include <wire/peer_wiregen.c>
+#endif
 #include <wire/fromwire.c>
 #include <wire/towire.c>