diff --git a/collects/scribble/html-render.ss b/collects/scribble/html-render.ss
index a8bdef8d..a8f75abd 100644
--- a/collects/scribble/html-render.ss
+++ b/collects/scribble/html-render.ss
@@ -584,7 +584,7 @@
         (cond
          [(string? i)
           (let ([m (and (extra-breaking?)
-                        (regexp-match-positions #rx"[-:/]" i))])
+                        (regexp-match-positions #rx"[-:/+]" i))])
             (if m
               (list* (substring i 0 (cdar m))
                      ;; Most browsers wrap after a hyphen. The