diff --git a/setup.c b/setup.c
index 1fc9ae3872..d407f3347b 100644
--- a/setup.c
+++ b/setup.c

@@ -632,6 +632,21 @@ static enum extension_result handle_extension_v0(const char *var,
 		return EXTENSION_UNKNOWN;
 }
 
+static void parse_reference_uri(const char *value, char **format,
+				char **payload)
+{
+	const char *schema_end;
+
+	schema_end = strstr(value, "://");
+	if (!schema_end) {
+		*format = xstrdup(value);
+		*payload = NULL;
+	} else {
+		*format = xstrndup(value, schema_end - value);
+		*payload = xstrdup_or_null(schema_end + 3);