diff --git a/gossipd/gossip_wire.csv b/gossipd/gossip_wire.csv
index 63392d87b..b9c988fb8 100644
--- a/gossipd/gossip_wire.csv
+++ b/gossipd/gossip_wire.csv
@@ -15,6 +15,10 @@ msgdata,gossipctl_init,num_announcable,u16,
 msgdata,gossipctl_init,announcable,wireaddr,num_announcable
 msgdata,gossipctl_init,dev_gossip_time,?u32,
 
+# In developer mode, we can mess with time.
+msgtype,gossip_dev_set_time,3001
+msgdata,gossip_dev_set_time,dev_gossip_time,u32,
+
 # Pass JSON-RPC getnodes call through
 msgtype,gossip_getnodes_request,3005
 msgdata,gossip_getnodes_request,id,?node_id,
diff --git a/gossipd/gossipd.c b/gossipd/gossipd.c
index cbf2acdde..81d0ea5f3 100644
--- a/gossipd/gossipd.c
+++ b/gossipd/gossipd.c
@@ -3065,6 +3065,22 @@ static struct io_plan *dev_compact_store(struct io_conn *conn,
 								    done)));
 	return daemon_conn_read_next(conn, daemon->master);
 }
+
+static struct io_plan *dev_gossip_set_time(struct io_conn *conn,
+					   struct daemon *daemon,
+					   const u8 *msg)
+{
+	u32 time;
+
+	if (!fromwire_gossip_dev_set_time(msg, &time))
+		master_badmsg(WIRE_GOSSIP_DEV_SET_TIME, msg);
+	if (!daemon->rstate->gossip_time)
+		daemon->rstate->gossip_time = tal(daemon->rstate, struct timeabs);
+	daemon->rstate->gossip_time->ts.tv_sec = time;
+	daemon->rstate->gossip_time->ts.tv_nsec = 0;
+
+	return daemon_conn_read_next(conn, daemon->master);
+}
 #endif /* DEVELOPER */
 
 /*~ lightningd: so, tell me about this channel, so we can forward to it. */
@@ -3339,6 +3355,8 @@ static struct io_plan *recv_req(struct io_conn *conn,
 		return dev_gossip_memleak(conn, daemon, msg);
 	case WIRE_GOSSIP_DEV_COMPACT_STORE:
 		return dev_compact_store(conn, daemon, msg);
+	case WIRE_GOSSIP_DEV_SET_TIME:
+		return dev_gossip_set_time(conn, daemon, msg);
 #else
 	case WIRE_GOSSIP_QUERY_SCIDS:
 	case WIRE_GOSSIP_SEND_TIMESTAMP_FILTER:
@@ -3347,6 +3365,7 @@ static struct io_plan *recv_req(struct io_conn *conn,
 	case WIRE_GOSSIP_DEV_SUPPRESS:
 	case WIRE_GOSSIP_DEV_MEMLEAK:
 	case WIRE_GOSSIP_DEV_COMPACT_STORE:
+	case WIRE_GOSSIP_DEV_SET_TIME:
 		break;
 #endif /* !DEVELOPER */
 
diff --git a/gossipd/test/run-crc32_of_update.c b/gossipd/test/run-crc32_of_update.c
index 900cbdb98..f84f4b90f 100644
--- a/gossipd/test/run-crc32_of_update.c
+++ b/gossipd/test/run-crc32_of_update.c
@@ -59,6 +59,9 @@ bool fromwire_gossipctl_init(const tal_t *ctx UNNEEDED, const void *p UNNEEDED,
 /* Generated stub for fromwire_gossip_dev_set_max_scids_encode_size */
 bool fromwire_gossip_dev_set_max_scids_encode_size(const void *p UNNEEDED, u32 *max UNNEEDED)
 { fprintf(stderr, "fromwire_gossip_dev_set_max_scids_encode_size called!\n"); abort(); }
+/* Generated stub for fromwire_gossip_dev_set_time */
+bool fromwire_gossip_dev_set_time(const void *p UNNEEDED, u32 *dev_gossip_time UNNEEDED)
+{ fprintf(stderr, "fromwire_gossip_dev_set_time called!\n"); abort(); }
 /* Generated stub for fromwire_gossip_dev_suppress */
 bool fromwire_gossip_dev_suppress(const void *p UNNEEDED)
 { fprintf(stderr, "fromwire_gossip_dev_suppress called!\n"); abort(); }
diff --git a/gossipd/test/run-extended-info.c b/gossipd/test/run-extended-info.c
index 2542ddb22..df9b9eaa2 100644
--- a/gossipd/test/run-extended-info.c
+++ b/gossipd/test/run-extended-info.c
@@ -82,6 +82,9 @@ bool fromwire_gossipctl_init(const tal_t *ctx UNNEEDED, const void *p UNNEEDED,
 /* Generated stub for fromwire_gossip_dev_set_max_scids_encode_size */
 bool fromwire_gossip_dev_set_max_scids_encode_size(const void *p UNNEEDED, u32 *max UNNEEDED)
 { fprintf(stderr, "fromwire_gossip_dev_set_max_scids_encode_size called!\n"); abort(); }
+/* Generated stub for fromwire_gossip_dev_set_time */
+bool fromwire_gossip_dev_set_time(const void *p UNNEEDED, u32 *dev_gossip_time UNNEEDED)
+{ fprintf(stderr, "fromwire_gossip_dev_set_time called!\n"); abort(); }
 /* Generated stub for fromwire_gossip_dev_suppress */
 bool fromwire_gossip_dev_suppress(const void *p UNNEEDED)
 { fprintf(stderr, "fromwire_gossip_dev_suppress called!\n"); abort(); }
diff --git a/lightningd/gossip_control.c b/lightningd/gossip_control.c
index caf2d6b03..3ebecac89 100644
--- a/lightningd/gossip_control.c
+++ b/lightningd/gossip_control.c
@@ -151,6 +151,7 @@ static unsigned gossip_msg(struct subd *gossip, const u8 *msg, const int *fds)
 	case WIRE_GOSSIP_LOCAL_CHANNEL_CLOSE:
 	case WIRE_GOSSIP_DEV_MEMLEAK:
 	case WIRE_GOSSIP_DEV_COMPACT_STORE:
+	case WIRE_GOSSIP_DEV_SET_TIME:
 	/* This is a reply, so never gets through to here. */
 	case WIRE_GOSSIP_GETNODES_REPLY:
 	case WIRE_GOSSIP_GETROUTE_REPLY:
@@ -762,4 +763,31 @@ static const struct json_command dev_compact_gossip_store = {
 	"Ask gossipd to rewrite the gossip store."
 };
 AUTODATA(json_command, &dev_compact_gossip_store);
+
+static struct command_result *json_dev_gossip_set_time(struct command *cmd,
+						       const char *buffer,
+						       const jsmntok_t *obj UNNEEDED,
+						       const jsmntok_t *params)
+{
+	u8 *msg;
+	u32 *time;
+
+	if (!param(cmd, buffer, params,
+		   p_req("time", param_number, &time),
+		   NULL))
+		return command_param_failed();
+
+	msg = towire_gossip_dev_set_time(NULL, *time);
+	subd_send_msg(cmd->ld->gossip, take(msg));
+
+	return command_success(cmd, json_stream_success(cmd));
+}
+
+static const struct json_command dev_gossip_set_time = {
+	"dev-gossip-set-time",
+	"developer",
+	json_dev_gossip_set_time,
+	"Ask gossipd to update the current time."
+};
+AUTODATA(json_command, &dev_gossip_set_time);
 #endif /* DEVELOPER */