Index: plug-ins/script-fu/tinyscheme/scheme.c
===================================================================
--- plug-ins/script-fu/tinyscheme/scheme.c	(revision 25670)
+++ plug-ins/script-fu/tinyscheme/scheme.c	(working copy)
@@ -2783,6 +2783,8 @@
                new_slot_in_env(sc, caar(x), car(y));
           }
           if (is_symbol(car(sc->code))) {    /* named let */
+               if (!is_pair(cadr(sc->code)))
+                    Error_0(sc, "Bad syntax in let : missing parentheses");
                for (x = cadr(sc->code), sc->args = sc->NIL; x != sc->NIL; x = cdr(x)) {
 
                     sc->args = cons(sc, caar(x), sc->args);
