diff --git a/lib/init-7.scm b/lib/init-7.scm
index d265789f..63bb917c 100644
--- a/lib/init-7.scm
+++ b/lib/init-7.scm
@@ -706,7 +706,8 @@
         (_reverse (rename 'reverse))
         (_vector->list (rename 'vector->list))
         (_list->vector (rename 'list->vector))
-        (_cons3 (rename 'cons-source)))
+        (_cons3 (rename 'cons-source))
+        (_underscore (rename '_)))
     (define ellipsis (if ellipsis-specified? (cadr expr) (rename '...)))
     (define lits (if ellipsis-specified? (car (cddr expr)) (cadr expr)))
     (define forms (if ellipsis-specified? (cdr (cddr expr)) (cddr expr)))
@@ -729,7 +730,9 @@
                  (list _and
                        (list _compare v (list _rename (list _quote p)))
                        (k vars))
-                 (list _let (list (list p v)) (k (cons (cons p dim) vars)))))
+                 (if (compare p _underscore)
+                     (k vars)
+                     (list _let (list (list p v)) (k (cons (cons p dim) vars))))))
             ((ellipsis? p)
              (cond
               ((not (null? (cdr (cdr p))))
diff --git a/tests/r7rs-tests.scm b/tests/r7rs-tests.scm
index 85328b89..a16d814c 100644
--- a/tests/r7rs-tests.scm
+++ b/tests/r7rs-tests.scm
@@ -460,6 +460,11 @@
     (part-2x (10 (+ 21 22) (31 32) (41 42) (51 52) (+ 61 2) 77 . "tail")))
 
 ;; underscore
+(define-syntax underscore
+  (syntax-rules ()
+    ((foo _) '_)))
+(test '_ (underscore foo))
+
 (define-syntax count-to-2
   (syntax-rules ()
     ((_) 0)