--- a/readcfg.c
+++ b/readcfg.c
@@ -2006,7 +2006,7 @@ static char *describe_addrtype(addrtype
 #ifdef BW_LIM
 char *describe_rate(long rate)
 {
-  static char buf[12];
+  static char buf[20];
   int c;
   if (rate == 0) return "-";
   else if (rate < 0) c = sprintf(buf, "%ld%%", -rate);
