diff --git a/ui/gfx/text_utils.cc b/ui/gfx/text_utils.cc
index a5a1b799..8a2658c 100644
--- a/ui/gfx/text_utils.cc
+++ b/ui/gfx/text_utils.cc
@@ -13,7 +13,7 @@
                                int* accelerated_char_pos,
                                int* accelerated_char_span) {
   bool escaped = false;
-  int last_char_pos = -1;
+  ptrdiff_t last_char_pos = -1;
   int last_char_span = 0;
   base::i18n::UTF16CharIterator chars(&s);
   string16 accelerator_removed;