diff --git a/lightningd/Makefile b/lightningd/Makefile
index 68b3191b5..62090aa4f 100644
--- a/lightningd/Makefile
+++ b/lightningd/Makefile
@@ -70,6 +70,7 @@ LIGHTNINGD_SRC :=				\
 	lightningd/lightningd.c			\
 	lightningd/log.c			\
 	lightningd/log_status.c			\
+	lightningd/memdump.c			\
 	lightningd/onchain_control.c		\
 	lightningd/opening_control.c		\
 	lightningd/options.c			\
@@ -83,11 +84,7 @@ LIGHTNINGD_SRC :=				\
 	lightningd/subd.c			\
 	lightningd/watch.c
 
-# Source files without corresponding headers
-LIGHTNINGD_SRC_NOHDR :=				\
-	lightningd/memdump.c
-
-LIGHTNINGD_OBJS := $(LIGHTNINGD_SRC:.c=.o) $(LIGHTNINGD_SRC_NOHDR:.c=.o)
+LIGHTNINGD_OBJS := $(LIGHTNINGD_SRC:.c=.o)
 
 # Make sure these depend on everything.
 ALL_OBJS += $(LIGHTNINGD_OBJS)
diff --git a/lightningd/memdump.c b/lightningd/memdump.c
index 383123d7c..8b7cba511 100644
--- a/lightningd/memdump.c
+++ b/lightningd/memdump.c
@@ -1,5 +1,5 @@
 /* Only possible if we're in developer mode. */
-#include "config.h"
+#include "memdump.h"
 #if DEVELOPER
 #include <backtrace.h>
 #include <ccan/tal/str/str.h>
@@ -15,6 +15,7 @@
 #include <lightningd/jsonrpc_errors.h>
 #include <lightningd/lightningd.h>
 #include <lightningd/log.h>
+#include <lightningd/opening_control.h>
 #include <lightningd/param.h>
 #include <lightningd/subd.h>
 #include <stdio.h>
@@ -254,13 +255,26 @@ static void hsm_dev_memleak_done(struct subd *hsmd,
 		 -1, 0, connect_dev_memleak_done, cmd);
 }
 
+void opening_memleak_done(struct command *cmd, struct subd *leaker)
+{
+	if (leaker)
+		report_leak_info(cmd, leaker);
+	else {
+		/* No leak there, try hsmd (we talk to hsm sync) */
+		u8 *msg = towire_hsm_dev_memleak(NULL);
+		if (!wire_sync_write(cmd->ld->hsm_fd, take(msg)))
+			fatal("Could not write to HSM: %s", strerror(errno));
+
+		hsm_dev_memleak_done(cmd->ld->hsm,
+				     wire_sync_read(tmpctx, cmd->ld->hsm_fd),
+				     cmd);
+	}
+}
+
 static void json_memleak(struct command *cmd,
 			 const char *buffer UNNEEDED,
 			 const jsmntok_t *params UNNEEDED)
 {
-	struct lightningd *ld = cmd->ld;
-	u8 *msg;
-
 	if (!param(cmd, buffer, params, NULL))
 		return;
 
@@ -274,12 +288,8 @@ static void json_memleak(struct command *cmd,
 	 * immediately. */
 	command_still_pending(cmd);
 
-	/* We talk to hsm sync. */
-	msg = towire_hsm_dev_memleak(NULL);
-	if (!wire_sync_write(ld->hsm_fd, take(msg)))
-		fatal("Could not write to HSM: %s", strerror(errno));
-
-	hsm_dev_memleak_done(ld->hsm, wire_sync_read(tmpctx, ld->hsm_fd), cmd);
+	/* This calls opening_memleak_done() async when all done. */
+	opening_dev_memleak(cmd);
 }
 
 static const struct json_command dev_memleak_command = {
diff --git a/lightningd/memdump.h b/lightningd/memdump.h
new file mode 100644
index 000000000..88741a364
--- /dev/null
+++ b/lightningd/memdump.h
@@ -0,0 +1,11 @@
+#ifndef LIGHTNING_LIGHTNINGD_MEMDUMP_H
+#define LIGHTNING_LIGHTNINGD_MEMDUMP_H
+#include "config.h"
+#include <ccan/short_types/short_types.h>
+#include <stdbool.h>
+
+struct command;
+struct subd;
+
+void opening_memleak_done(struct command *cmd, struct subd *leaker);
+#endif /* LIGHTNING_LIGHTNINGD_MEMDUMP_H */
diff --git a/lightningd/opening_control.c b/lightningd/opening_control.c
index 9e1ad1bdf..6a4c375ff 100644
--- a/lightningd/opening_control.c
+++ b/lightningd/opening_control.c
@@ -675,6 +675,9 @@ static unsigned int openingd_msg(struct subd *openingd,
 	case WIRE_OPENING_INIT:
 	case WIRE_OPENING_FUNDER:
 	case WIRE_OPENING_CAN_ACCEPT_CHANNEL:
+	case WIRE_OPENING_DEV_MEMLEAK:
+	/* Replies never get here */
+	case WIRE_OPENING_DEV_MEMLEAK_REPLY:
 		break;
 	}
 	log_broken(openingd->log, "Unexpected msg %s: %s",
@@ -855,3 +858,58 @@ static const struct json_command fund_channel_command = {
 	"Fund channel with {id} using {satoshi} (or 'all') satoshis, at optional {feerate}"
 };
 AUTODATA(json_command, &fund_channel_command);
+
+#if DEVELOPER
+ /* Indented to avoid include ordering check */
+ #include <lightningd/memdump.h>
+
+/* Mutual recursion */
+static void opening_memleak_req_next(struct command *cmd, struct peer *prev);
+static void opening_memleak_req_done(struct subd *openingd,
+				     const u8 *msg, const int *fds UNUSED,
+				     struct command *cmd)
+{
+	bool found_leak;
+	struct uncommitted_channel *uc = openingd->channel;
+
+	if (!fromwire_opening_dev_memleak_reply(msg, &found_leak)) {
+		command_fail(cmd, LIGHTNINGD, "Bad opening_dev_memleak");
+		return;
+	}
+
+	if (found_leak) {
+		opening_memleak_done(cmd, openingd);
+		return;
+	}
+	opening_memleak_req_next(cmd, uc->peer);
+}
+
+static void opening_memleak_req_next(struct command *cmd, struct peer *prev)
+{
+	struct peer *p;
+
+	list_for_each(&cmd->ld->peers, p, list) {
+		if (!p->uncommitted_channel)
+			continue;
+		if (p == prev) {
+			prev = NULL;
+			continue;
+		}
+		if (prev != NULL)
+			continue;
+
+		/* FIXME: If openingd dies, we'll get stuck here! */
+		subd_req(p,
+			 p->uncommitted_channel->openingd,
+			 take(towire_opening_dev_memleak(NULL)),
+			 -1, 0, opening_memleak_req_done, cmd);
+		return;
+	}
+	opening_memleak_done(cmd, NULL);
+}
+
+void opening_dev_memleak(struct command *cmd)
+{
+	opening_memleak_req_next(cmd, NULL);
+}
+#endif /* DEVELOPER */
diff --git a/lightningd/opening_control.h b/lightningd/opening_control.h
index fc0287c01..616ae1680 100644
--- a/lightningd/opening_control.h
+++ b/lightningd/opening_control.h
@@ -22,4 +22,10 @@ void opening_peer_no_active_channels(struct peer *peer);
 void kill_uncommitted_channel(struct uncommitted_channel *uc,
 			      const char *why);
 
+#if DEVELOPER
+struct command;
+/* Calls report_leak_info() async. */
+void opening_dev_memleak(struct command *cmd);
+#endif
+
 #endif /* LIGHTNING_LIGHTNINGD_OPENING_CONTROL_H */
diff --git a/openingd/opening_wire.csv b/openingd/opening_wire.csv
index 5a25577c5..72cb9fb70 100644
--- a/openingd/opening_wire.csv
+++ b/openingd/opening_wire.csv
@@ -85,3 +85,9 @@ opening_fundee,,feerate_per_kw,u32
 opening_fundee,,msglen,u16
 opening_fundee,,funding_signed_msg,msglen*u8
 opening_fundee,,our_channel_reserve_satoshis,u64
+
+# master -> openingd: do you have a memleak?
+opening_dev_memleak,6033
+
+opening_dev_memleak_reply,6133
+opening_dev_memleak_reply,,leak,bool
diff --git a/openingd/openingd.c b/openingd/openingd.c
index 72060c76c..d9813a278 100644
--- a/openingd/openingd.c
+++ b/openingd/openingd.c
@@ -13,6 +13,7 @@
 #include <common/gen_peer_status_wire.h>
 #include <common/initial_channel.h>
 #include <common/key_derive.h>
+#include <common/memleak.h>
 #include <common/peer_billboard.h>
 #include <common/peer_failed.h>
 #include <common/pseudorand.h>
@@ -1043,6 +1044,24 @@ static void fail_if_all_error(const u8 *inner)
 	exit(0);
 }
 
+#if DEVELOPER
+static void handle_dev_memleak(struct state *state, const u8 *msg)
+{
+	struct htable *memtable;
+	bool found_leak;
+
+	memtable = memleak_enter_allocations(tmpctx, msg, msg);
+
+	/* Now delete state and things it has pointers to. */
+	memleak_remove_referenced(memtable, state);
+
+	found_leak = dump_memleak(memtable);
+	wire_sync_write(REQ_FD,
+			take(towire_opening_dev_memleak_reply(NULL,
+							      found_leak)));
+}
+#endif /* DEVELOPER */
+
 static u8 *handle_master_in(struct state *state)
 {
 	u8 *msg = wire_sync_read(tmpctx, REQ_FD);
@@ -1076,6 +1095,12 @@ static u8 *handle_master_in(struct state *state)
 		state->can_accept_channel = true;
 		return NULL;
 
+	case WIRE_OPENING_DEV_MEMLEAK:
+#if DEVELOPER
+		handle_dev_memleak(state, msg);
+		return NULL;
+#endif
+	case WIRE_OPENING_DEV_MEMLEAK_REPLY:
 	case WIRE_OPENING_INIT:
 	case WIRE_OPENING_FUNDER_REPLY:
 	case WIRE_OPENING_FUNDEE: