diff --git a/lightningd/lightningd.c b/lightningd/lightningd.c
index 66c5c289a..429b20807 100644
--- a/lightningd/lightningd.c
+++ b/lightningd/lightningd.c
@@ -278,6 +278,15 @@ static void pidfile_create(const struct lightningd *ld)
 	write_all(pid_fd, pid, strlen(pid));
 }
 
+/* Yuck, we need globals here. */
+static int (*io_poll_debug)(struct pollfd *, nfds_t, int);
+static int io_poll_lightningd(struct pollfd *fds, nfds_t nfds, int timeout)
+{
+	db_assert_no_outstanding_statements();
+
+	return io_poll_debug(fds, nfds, timeout);
+}
+
 int main(int argc, char *argv[])
 {
 	setup_locale();
@@ -310,6 +319,9 @@ int main(int argc, char *argv[])
 	ld->owned_txfilter = txfilter_new(ld);
 	ld->topology->wallet = ld->wallet;
 
+	/* We do extra checks in io_loop. */
+	io_poll_debug = io_poll_override(io_poll_lightningd);
+
 	/* Set up HSM. */
 	hsm_init(ld, newdir);
 
diff --git a/lightningd/test/run-find_my_path.c b/lightningd/test/run-find_my_path.c
index f6a3db300..6eca73222 100644
--- a/lightningd/test/run-find_my_path.c
+++ b/lightningd/test/run-find_my_path.c
@@ -18,6 +18,9 @@ void daemon_setup(const char *argv0 UNNEEDED,
 /* Generated stub for daemon_shutdown */
 void daemon_shutdown(void)
 { fprintf(stderr, "daemon_shutdown called!\n"); abort(); }
+/* Generated stub for db_assert_no_outstanding_statements */
+void db_assert_no_outstanding_statements(void)
+{ fprintf(stderr, "db_assert_no_outstanding_statements called!\n"); abort(); }
 /* Generated stub for db_begin_transaction_ */
 void db_begin_transaction_(struct db *db UNNEEDED, const char *location UNNEEDED)
 { fprintf(stderr, "db_begin_transaction_ called!\n"); abort(); }