diff --git a/tests/io-tests.scm b/tests/io-tests.scm
index db064f5a..563590e0 100644
--- a/tests/io-tests.scm
+++ b/tests/io-tests.scm
@@ -111,6 +111,11 @@
                (list "日本語" (make-string 4087 #\-) "abc"))))
       (read-string 4090 in)
       (read-line in)))
+(test "abc"
+    (let ((in (strings->input-port
+               (list "日本語" (make-string 4087 #\本) "abc"))))
+      (read-string 4090 in)
+      (read-line in)))
 (test "abc"
     (let ((in (strings->input-port
                (list "日本語" (make-string 4093 #\-) "abc"))))