diff --git a/plugins/autoclean.c b/plugins/autoclean.c
index 1da6c66e5..3e45df829 100644
--- a/plugins/autoclean.c
+++ b/plugins/autoclean.c
@@ -84,10 +84,12 @@ int main(int argc, char *argv[])
 	setup_locale();
 	plugin_main(argv, init, commands, ARRAY_SIZE(commands),
 		    plugin_option("autocleaninvoice-cycle",
+				  "string",
 				  "Perform cleanup of expired invoices every"
 				  " given seconds, or do not autoclean if 0",
 				  u64_option, &cycle_seconds),
 		    plugin_option("autocleaninvoice-expired-by",
+				  "string",
 				  "If expired invoice autoclean enabled,"
 				  " invoices that have expired for at least"
 				  " this given seconds are cleaned",
diff --git a/plugins/libplugin.c b/plugins/libplugin.c
index ea1e118b2..68fb3d1fe 100644
--- a/plugins/libplugin.c
+++ b/plugins/libplugin.c
@@ -439,11 +439,12 @@ handle_getmanifest(struct command *getmanifest_cmd,
 
 	for (size_t i = 0; i < tal_count(opts); i++) {
 		tal_append_fmt(&params, "{ 'name': '%s',"
-			       "    'type': 'string',"
-			       "    'description': '%s' }%s",
-			       opts[i].name,
-			       opts[i].description,
-			       i == tal_count(opts) - 1 ? "" : ",\n");
+				"    'type': '%s',"
+				"    'description': '%s' }%s",
+				opts[i].name,
+				opts[i].type,
+				opts[i].description,
+				i == tal_count(opts) - 1 ? "" : ",\n");
 	}
 
 	tal_append_fmt(&params,
@@ -507,7 +508,6 @@ static struct command_result *handle_init(struct command *init_cmd,
 					  &rpc_conn,
 					  ".allow-deprecated-apis"),
 				"true");
-
 	opttok = json_get_member(buf, params, "options");
 	json_for_each_obj(i, t, opttok) {
 		char *opt = json_strdup(NULL, buf, t);
@@ -695,6 +695,7 @@ void plugin_main(char *argv[],
 	while ((optname = va_arg(ap, const char *)) != NULL) {
 		struct plugin_option o;
 		o.name = optname;
+		o.type = va_arg(ap, const char *);
 		o.description = va_arg(ap, const char *);
 		o.handle = va_arg(ap, char *(*)(const char *str, void *arg));
 		o.arg = va_arg(ap, void *);
diff --git a/plugins/libplugin.h b/plugins/libplugin.h
index fc7ca1992..dc3ce911f 100644
--- a/plugins/libplugin.h
+++ b/plugins/libplugin.h
@@ -29,6 +29,7 @@ struct plugin_command {
 /* Create an array of these, one for each --option you support. */
 struct plugin_option {
 	const char *name;
+	const char *type;
 	const char *description;
 	char *(*handle)(const char *str, void *arg);
 	void *arg;
@@ -119,8 +120,9 @@ struct plugin_timer *plugin_timer(struct plugin_conn *rpc,
 void PRINTF_FMT(2, 3) plugin_log(enum log_level l, const char *fmt, ...);
 
 /* Macro to define arguments */
-#define plugin_option(name, description, set, arg)			\
+#define plugin_option(name, type, description, set, arg)			\
 	(name),								\
+	(type),								\
 	(description),							\
 	typesafe_cb_preargs(char *, void *, (set), (arg), const char *),	\
 	(arg)