diff --git a/tests/r7rs-tests.scm b/tests/r7rs-tests.scm
index 1c9aecc8..74c734af 100644
--- a/tests/r7rs-tests.scm
+++ b/tests/r7rs-tests.scm
@@ -439,6 +439,26 @@
 (be-like-begin3 sequence3)
 (test 5 (sequence3 2 3 4 5))
 
+;; underscore
+(define-syntax count-to-2
+  (syntax-rules ()
+    ((_) 0)
+    ((_ _) 1)
+    ((_ _ _) 2)
+    ((_ . _) 'many)))
+(test '(2 0 many)
+    (list (count-to-2 a b) (count-to-2) (count-to-2 a b c d)))
+
+(define-syntax count-to-2_
+  (syntax-rules (_)
+    ((_) 0)
+    ((_ _) 1)
+    ((_ _ _) 2)
+    ((x . y) 'fail)))
+(test '(2 0 fail fail)
+    (list (count-to-2_ _ _) (count-to-2_)
+          (count-to-2_ a b) (count-to-2_ a b c d)))
+
 (define-syntax jabberwocky
   (syntax-rules ()
     ((_ hatter)