diff --git a/lib/dns/tests/rbt_serialize_test.c b/lib/dns/tests/rbt_serialize_test.c
index 2208c0d8e7..51ebffc5b3 100644
--- a/lib/dns/tests/rbt_serialize_test.c
+++ b/lib/dns/tests/rbt_serialize_test.c
@@ -173,7 +173,7 @@ write_data(FILE *file, unsigned char *datap, void *arg, uint64_t *crc) {
 
 static isc_result_t
 fix_data(dns_rbtnode_t *p, void *base, size_t max, void *arg, uint64_t *crc) {
-	data_holder_t *data = p->data;
+	data_holder_t *data;
 	size_t size;
 
 	UNUSED(base);
@@ -183,6 +183,7 @@ fix_data(dns_rbtnode_t *p, void *base, size_t max, void *arg, uint64_t *crc) {
 	REQUIRE(crc != NULL);
 	REQUIRE(p != NULL);
 
+	data = p->data;
 
 	if (data == NULL ||
 	    (data->len == 0 && data->data != NULL) ||