diff --git a/lib/init-7.scm b/lib/init-7.scm
index 8a3ea91f..6d1d68cb 100644
--- a/lib/init-7.scm
+++ b/lib/init-7.scm
@@ -873,8 +873,8 @@
       (set! count (+ count 1))
       (rename (string->symbol (string-append s (%number->string count)))))
     (define (expand-pattern pat tmpl)
-      (let lp ((p (cdr pat))
-               (x (list _cdr _expr))
+      (let lp ((p (if (pair? pat) (cdr pat) pat))
+               (x (if (pair? pat) (list _cdr _expr) _expr))
                (dim 0)
                (vars '())
                (k (lambda (vars)