diff --git a/main/dns_test.c b/main/dns_test.c
index 3d61692590de260da91757cd2c65af36f068844d..5ec994aed7e6e9adbb15f9495f0d12694b79f507 100644
--- a/main/dns_test.c
+++ b/main/dns_test.c
@@ -246,7 +246,7 @@ int ast_dns_test_generate_result(struct ast_dns_query *query, void *records, siz
 
 #else /* TEST_FRAMEWORK */
 
-int ast_dns_test_write_string(struct ast_dns_test_string *string, char *buf)
+int ast_dns_test_write_string(const struct ast_dns_test_string *string, char *buf)
 {
 	return 0;
 }