1 files changed, 2 insertions, 1 deletions

diff --git a/src/casefiddle.c b/src/casefiddle.c
index 9545cf697a8..815f684e26a 100644
--- a/src/casefiddle.c
+++ b/src/casefiddle.c
@@ -243,7 +243,8 @@ casify_region (enum case_action flag, Lisp_Object b, Lisp_Object e)
                && (!inword || flag != CASE_CAPITALIZE_UP))
         c = UPCASE1 (c);
       if ((int) flag >= (int) CASE_CAPITALIZE)
-        inword = ((SYNTAX (c) == Sword) && (inword || !SYNTAX_PREFIX (c)));
+        inword = ((SYNTAX (c) == Sword)
+                  && (inword || !syntax_prefix_flag_p (c)));
       if (c != c2)
         {
           last = start;