diff --git a/plugins/libplugin.c b/plugins/libplugin.c
index b39058d46..db2e53fb7 100644
--- a/plugins/libplugin.c
+++ b/plugins/libplugin.c
@@ -1688,6 +1688,14 @@ char *charp_option(struct command *cmd, const char *arg, bool check_only, char *
 	return NULL;
 }
 
+char *multi_string_option(struct command *cmd, const char *arg, bool check_only,
+			  const char ***arr)
+{
+	if (!check_only)
+		tal_arr_expand(arr, tal_strdup(*arr, arg));
+	return NULL;
+}
+
 bool u64_jsonfmt(struct command *cmd, struct json_stream *js, const char *fieldname, u64 *i)
 {
 	json_add_u64(js, fieldname, *i);
@@ -1720,6 +1728,16 @@ bool charp_jsonfmt(struct command *cmd, struct json_stream *js, const char *fiel
 	return true;
 }
 
+bool string_array_jsonfmt(struct command *cmd, struct json_stream *js,
+			  const char *fieldname, const char ***arr)
+{
+	json_array_start(js, fieldname);
+	for (size_t i = 0; i < tal_count(*arr); i++)
+		json_add_string(js, NULL, (*arr)[i]);
+	json_array_end(js);
+	return true;
+}
+
 bool flag_jsonfmt(struct command *cmd, struct json_stream *js, const char *fieldname, bool *i)
 {
 	/* Don't print if the default (false) */
diff --git a/plugins/libplugin.h b/plugins/libplugin.h
index bddba28f7..3e435f65e 100644
--- a/plugins/libplugin.h
+++ b/plugins/libplugin.h
@@ -638,6 +638,8 @@ char *u32_option(struct command *cmd, const char *arg, bool check_only, u32 *i);
 char *u16_option(struct command *cmd, const char *arg, bool check_only, u16 *i);
 char *bool_option(struct command *cmd, const char *arg, bool check_only, bool *i);
 char *charp_option(struct command *cmd, const char *arg, bool check_only, char **p);
+char *multi_string_option(struct command *cmd, const char *arg, bool check_only,
+			  const char ***arr);
 char *flag_option(struct command *cmd, const char *arg, bool check_only, bool *i);
 
 bool u64_jsonfmt(struct command *cmd, struct json_stream *js, const char *fieldname,
@@ -650,6 +652,8 @@ bool bool_jsonfmt(struct command *cmd, struct json_stream *js, const char *field
 		  bool *i);
 bool charp_jsonfmt(struct command *cmd, struct json_stream *js, const char *fieldname,
 		   char **p);
+bool string_array_jsonfmt(struct command *cmd, struct json_stream *js,
+			  const char *fieldname, const char ***arr);
 
 /* Usually equivalent to NULL, since flag must default to false be useful! */
 bool flag_jsonfmt(struct command *cmd, struct json_stream *js, const char *fieldname,
diff --git a/tests/plugins/test_libplugin.c b/tests/plugins/test_libplugin.c
index a89b61649..907d5c4b4 100644
--- a/tests/plugins/test_libplugin.c
+++ b/tests/plugins/test_libplugin.c
@@ -372,25 +372,6 @@ static const struct plugin_notification notifs[] = { {
 	}
 };
 
-static char *set_multi_string_option(struct command *cmd,
-				     const char *arg,
-				     bool check_only,
-				     const char ***arr)
-{
-	if (!check_only)
-		tal_arr_expand(arr, tal_strdup(*arr, arg));
-	return NULL;
-}
-
-static bool multi_string_jsonfmt(struct command *cmd, struct json_stream *js, const char *fieldname, const char ***arr)
-{
-	json_array_start(js, fieldname);
-	for (size_t i = 0; i < tal_count(*arr); i++)
-		json_add_string(js, NULL, (*arr)[i]);
-	json_array_end(js);
-	return true;
-}
-
 int main(int argc, char *argv[])
 {
 	setup_locale();
@@ -436,8 +417,8 @@ int main(int argc, char *argv[])
 		    plugin_option_multi("multiopt",
 					"string",
 					"Set me multiple times!",
-					set_multi_string_option,
-					multi_string_jsonfmt,
+					multi_string_option,
+					string_array_jsonfmt,
 					&tlp->strarr),
 		    NULL);
 }