diff --git a/tests/r7rs-tests.scm b/tests/r7rs-tests.scm
index 939a9621..184e25d2 100644
--- a/tests/r7rs-tests.scm
+++ b/tests/r7rs-tests.scm
@@ -1763,6 +1763,18 @@
 (test "abc" (read-string 3 (open-input-string "abcd")))
 (test "abc" (read-string 3 (open-input-string "abc\ndef\n")))
 
+(let* ((s (string #\x1F700 #\x1F701 #\x1F702))
+       (in (open-input-string s)))
+  (test #\x1F700 (string-ref s 0))
+  (test #\x1F701 (string-ref s 1))
+  (test #\x1F702 (string-ref s 2))
+  (let* ((c1 (read-char in))
+         (c2 (read-char in))
+         (c3 (read-char in)))
+    (test #\x1F700 c1)
+    (test #\x1F701 c2)
+    (test #\x1F702 c3)))
+
 (test "abc"
     (let ((out (open-output-string)))
       (write 'abc out)