diff --git a/src/core/core-url.c b/src/core/core-url.c
index 34893a994..cbbee3be8 100644
--- a/src/core/core-url.c
+++ b/src/core/core-url.c
@@ -125,7 +125,9 @@ struct t_url_constant url_auth[] =
     URL_DEF_CONST(AUTH, NTLM),
     URL_DEF_CONST(AUTH, ANY),
     URL_DEF_CONST(AUTH, ANYSAFE),
+#if LIBCURL_VERSION_NUM < 0x081500 /* < 8.21.0 */
     URL_DEF_CONST(AUTH, DIGEST_IE),
+#endif
     URL_DEF_CONST(AUTH, ONLY),
 #if LIBCURL_VERSION_NUM < 0x080800 /* < 8.8.0 */
     URL_DEF_CONST(AUTH, NTLM_WB),