diff --git a/ext/ftp/ftp.c b/ext/ftp/ftp.c
index 1345e378d8e3..31ec7dc7343a 100644
--- a/ext/ftp/ftp.c
+++ b/ext/ftp/ftp.c
@@ -1904,7 +1904,10 @@ data_accept(databuf_t *data, ftpbuf_t *ftp)
 		/* get the session from the control connection so we can re-use it */
 		session = ftp->last_ssl_session;
 		if (session == NULL) {
-			php_error_docref(NULL, E_WARNING, "data_accept: failed to retrieve the existing SSL session");
+			php_error_docref(NULL, E_WARNING, "data_accept: failed to retrieve the existing SSL session from the control connection. "
+											  "The server does not support TLS session resumption on the data connection, "
+											  "which is necessary to protect against session data stealing. "
+											  "PHP does not support such configuration.");
 			SSL_free(data->ssl_handle);
 			return 0;
 		}