diff --git a/lib/chibi/term/edit-line.scm b/lib/chibi/term/edit-line.scm
index c19ddf51..f49c1c85 100644
--- a/lib/chibi/term/edit-line.scm
+++ b/lib/chibi/term/edit-line.scm
@@ -284,7 +284,7 @@
       ((<= #xFFE0 ci #xFFE6) 2)
       ((<= #x20000 ci #x30000) 2)
       ;; non-spacing mark (Mn) ranges from UnicodeData.txt
-      ((<= #x0300 ci #x06bd)  ; #x3029
+      ((<= #x0300 ci #x20fd)  ; #x3029
        ;; inlined bit-vector-ref for portability
        (let* ((i (- ci #x0300))
               (byte (quotient i 8))