diff --git a/lib/xy.h b/lib/xy.h
index 2faff3a9..37c17713 100644
--- a/lib/xy.h
+++ b/lib/xy.h
@@ -473,6 +473,8 @@ static char *
 _xy_str_to_terminal_style (int style, const char *str)
 {
   char *color_fmt_str = NULL;
+  size_t len;
+  char *buf;
 
   if (!xy.enable_color)
     {
@@ -511,8 +513,8 @@ _xy_str_to_terminal_style (int style, const char *str)
 
 new_str:
   // -2 把中间%s减掉
-  size_t len = strlen (color_fmt_str) - 2;
-  char *buf = malloc (strlen (str) + len + 1);
+  len = strlen (color_fmt_str) - 2;
+  buf = malloc (strlen (str) + len + 1);
   sprintf (buf, color_fmt_str, str);
   return buf;
 }