diff --git a/ext/curl/interface.c b/ext/curl/interface.c
index 35339911bad0d..14836cc5ab3a3 100644
--- a/ext/curl/interface.c
+++ b/ext/curl/interface.c
@@ -1105,6 +1105,10 @@ PHP_MINIT_FUNCTION(curl)
 	REGISTER_CURL_CONSTANT(CURLOPT_DNS_SERVERS);
 #endif
 
+#if LIBCURL_VERSION_NUM >= 0x071900 /* Available since 7.25.0 */
+	REGISTER_CURL_CONSTANT(CURLOPT_MAIL_AUTH);
+#endif
+
 #if CURLOPT_FTPASCII != 0
 	REGISTER_CURL_CONSTANT(CURLOPT_FTPASCII);
 #endif
@@ -2214,6 +2218,9 @@ static int _php_curl_setopt(php_curl *ch, long option, zval **zvalue, zval *retu
 #if LIBCURL_VERSION_NUM >= 0x071800 /* Available since 7.24.0 */
 		case CURLOPT_DNS_SERVERS:
 #endif	
+#if LIBCURL_VERSION_NUM >= 0x071900 /* Available since 7.25.0 */
+		case CURLOPT_MAIL_AUTH:
+#endif
 		{
 #if LIBCURL_VERSION_NUM < 0x071100
 			char *copystr = NULL;