diff --git a/lisp/international/characters.el b/lisp/international/characters.el
index d856693261b..024333c4a88 100644
--- a/lisp/international/characters.el
+++ b/lisp/international/characters.el
@@ -916,7 +916,8 @@
   ;; Latin Extended-A, Latin Extended-B, IPA
   (setq c #x0100)
   (while (<= c #x02AF)
-    (modify-category-entry (decode-char 'ucs c) ?l))
+    (modify-category-entry (decode-char 'ucs c) ?l)
+    (setq c (1+ c)))
 
   (setq c #x0100)
   (while (<= c #x0177)